Allow Me to Vent

This is a post I have mentally debated writing for awhile now.  Like most bloggers (I think), I try to keep this place upbeat and certainly try to not publish anything that I may one day regret.
Unfortunately, though, we have some drama going on in our lives, and I've decided it's time to air the dirty laundry if you will.  Why?  Well, mainly just to get it off my chest and say my peace.  For awhile I worried that my in-laws may read this (since sadly they're the ones with whom we have our drama...), but honestly, I'm not saying anything here I wouldn't say to their face if they'd bother to listen!  And as an added incentive, I'm thinking if I go ahead and put this out there (and someone manages to read the marathon post), I may be able to hear some new perspectives.  My friends and family here have been wonderful over the past couple years and have oftentimes voiced their support and given us advice.  Maybe, though, someone out there has a different view...can point out something we've done wrong or offer some advice as to what we should do now.
So pour yourself a cup of coffee (although a stiff ole drink may be more appropriate) and try to keep up with what is sure to be a long post...
When Josh and I met, he had very little relationship with his parents.  Family has always been important to me, and as he and I got closer, so did his relationship with his family.  I'm not necessarily taking credit for their newfound bond, but I did have something to do with it.  Despite the fact that we came from very different worlds, his mom loved me...called me the daughter she never had.  His parents invited us over for weekly dinners at their house, helped us paint when we bought a new house, etc.
Flash forward to October 2010...my brother-in-law was getting married and my in-laws had asked us to host a rehearsal dinner at our house for the two families.  We all know I love a party, so I agreed.  The whole thing was much more stressful than I really had thought it would be, and it probably didn't help that I had just gone back to work after having Colton and was learning to juggle the start of a school year with my mom guilt.  The agreement was that I would take care of the decorating, cooking, etc, but that his mom would come over to watch Colton for me so I could get this stuff done.  I had also asked that they take Chipper to their house during the party considering he can't really handle crowds.  Josh's parents have never really liked Chipper, so we hadn't quite reached an agreement on that point!  Saturday comes, and I'm busy trying to get stuff ready and watch Colton because Josh's mom is nowhere to be seen.  She showed up around noon, stayed for about an hour, and when she went to leave she said something to the effect of "how am I even supposed to get Chipper to our house?"  I didn't really want any more drama or to spend an hour talking about Chipper, so I said (probably with some attitude if we're going to be honest) something to the effect of "never mind."  Well, she snapped...started yelling at me, saying how dare I talk to her like that, and left the house crying (without Chipper!).  I was pretty taken aback but didn't really think too much about it.
A few hours later she called.  Assuming she was calling to apologize or at least say she over-reacted, I answered.  HOLY CRAP!  She continued to lay into me.  I don't remember the exact words, but I was called selfish (as I'm knee deep in hosting a rehearsal dinner for her...) and yelled at worse than anyone has ever yelled at me in my life!  I hung up bawling and in total shock.
She called my mom a couple of days later to say she knew she had messed up and asked how to fix it (don't ask me why she didn't just call me).  My mom told her just to apologize and it would be fine.  A couple of days later, she showed up at our house and said...and I quote..."well, Michelle, I guess I'm supposed to apologize."  Even with that half-heartedness, I told her I appreciated it, but that I wasn't used to someone talking to me like that and I may take awhile to feel 100% comfortable again.  Well, clearly that was the wrong answer because she stormed out again...
From that day forward, our relationship with Josh's parents has been nothing but drama and pettiness.  I won't tell you about every issue, but about once a month or so his mom would call him or me or both of us yelling about something...that we only got his dad one birthday card and not two (one from us and Colton was supposedly necessary), that I had asked who she wanted to invite to Colton's birthday party because I guess that meant I didn't consider her family anymore despite the fact that I had done that for every single shower or party we had ever had, that we hadn't put some clothes on hangers yet (that were size 2t when Colton was just almost a year) so that must mean we didn't appreciate them enough.  In the meantime, they made absolutely no effort to get to know Colton (and later Levi)...those weekly dinners were a thing of the past, they didn't come over to visit, or even offer to watch him for us...nothing.
Last Thanksgiving I reached my breaking point.  His mom had brought over some flowers.  Clearly I'm the type of person who has put thought into my Thanksgiving centerpieces, so they weren't going on the main dining table!  But I did put them as a decoration near the appetizers.  Well, that wasn't good enough because not only did she complain to Josh as she left ("if she doesn't appreciate them...," followed by a "yeah, a real happy Thanksgiving"), she actually called the next day and came back to pick them up!  I told Josh that I would no longer be the target and was therefore done trying with his mom.
Over the past year, we've had very little contact with them.  They don't try to see our children...or us.  We've even showed up to their house (when they knew we were coming) to find Josh's brother and his wife over for dinner.  And if it matters, I also know that they are still invited for the weekly dinners.  But whatever. There was no drama.  As someone who despises confrontation, I was happier with this new arrangement than with what we had experienced the previous year.
And then shit hit the fan again.  A few days before we were scheduled to leave for our doomed Nashville trip, Josh's mom called ranting and raving again because she didn't know the kids and had no idea how she was supposed to take care of them because I hadn't called her yet (they were supposed to watch them during the days since my sister was working).  Josh told her we had planned on coming over the next day to go over everything, but she said that wasn't good enough because she had called us (?).  So then Josh said if it was so difficult, we would just find someone else to watch them...which we did.  A few days later he called her back and she told him they didn't want to see us at Thanksgiving or Christmas.  And just this week (about two weeks later), I got a call from Josh's grandmother who clearly had been fed some pretty shitty stories (none of them true) about us from his parents.  We talked it out, but I was pretty appalled that they would go so far as to attempt to sabotage Josh's relationship with his grandparents.
So here we are, and I don't know what to do.  I want Josh to have a relationship with his parents, and I want my boys to have a relationship with their grandparents...but only if it's a positive, loving one.  I'm very sick of being made the target of this and hearing time and time again that they are kept from their grandchildren (for the record, we have never not gone over to their house if invited nor said no to them visiting the boys...they just haven't done either for quite some time!)  And mostly I just want to move on and spend our energy focused on repairing the relationship (if that's possible) instead of trying to prove who the victim is.
We tried sitting down for a conversation with them way back at the beginning of all this and it quickly got unproductive...they're yellers (Josh included it seems), so it was just a bunch of finger pointing and no real progress.  Honestly, I think therapy would be best or at least having a mediator present at a conversation, but neither Josh nor I think they would go for that.  So, we've decided to write them a letter explaining what has hurt us over the couple of years and asking them to do the same.  Both of us half suspect that they'll be pissed or not even respond, but it was the only thing I could think of to try.  So now we wait...
In the mean time, please tell me someone out there has some sort of similar experience that eventually worked itself out.  Or some advice?