CRISIS!

I had a nice little post about chocolate chip cookies in a mug planned for today, but unfortunately that is going to have to be postponed because we are having a major problem in this house.  I am 1000% frustrated and stumped and really hoping that someone out there has some advice, guidance, suggestions, or SOMETHING!
At about 3 months of age, Levi started taking a regularly scheduled nap.  It was a challenge to get him on track for a couple of weeks, but eventually he got the hang of things and has been taking a nap at 2PM every day since with no problems. He generally sleeps about 2 hours...sometimes a little less, sometimes a little more. (He also takes a quick morning nap, but that is usually done in the car while we are out in and about and is not scheduled...just whenever he falls asleep.)
And to preface this...yes, I let Levi "cry it out."  It worked for us a couple other times, and I don't think there have been any major psychological wounds.
So, Friday I put him down for his nap. After about 45 minutes, he woke up crying.  I thought there was no way he was ready to get up yet, so I tried to leave him in there to go back to sleep.  After about 45 minutes, though, of incessant crying, I figured he must be ready to get up and I went in there to get him.  I'm now thinking that was a big mistake!
On Saturday, we stayed home all day due to the snow.  I really didn't give any thought to the day before's issues and was thinking he would take a morning nap and then we could go outside and play.  So, at 10, I put him down.  Well, he cried and cried and cried some more!  At this point, I knew we were having a little battle and figured he would just have to stay in there until he finally fell asleep, no matter how long it took.  Colton and I were hanging out in the den, but when Josh called (he was out getting his hair cut), Colton slyly snuck into Levi's crib.  Needless to say, there was no way Levi was going back to sleep at that point.  So, he came out...Levi:1, Mom:0.  And from that point forward, I knew we were in for a big battle.
Saturday afternoon we prepared to put him down for his regularly scheduled 2PM nap.  The boy was exhausted...barely keeping his eyes open, cuddling, etc.  I read him his book like normal, but as soon as I stood up and started walking towards the crib, he started crying.  And didn't stop for 2 hours and 45 minutes!!!  Seriously, y'all!  At one point, I even googled "how long can a baby cry?"  It was awful.  I watched him on the monitor the whole time and he just stood at the end of his crib closest to the door the entire time...pathetic!  And after the 2 hours and 45 minutes, he didn't even fall asleep...he was just sitting in his crib.  But we were taking the boys to my parents house that night and at this point it was already almost 5, so I figured it was better to get him when he wasn't crying than run the risk of him starting up again.  So we got him, left for my parents, and he fell asleep within minutes of being in the car.
By the time we got to Sunday afternoon's nap, I was absolutely dreading it.  And turns out I had good reason to!  This time he cried for 3 hours...literally...but I was determined that he fall asleep.  And he finally did at 5:00 sitting up in his crib.  I watched his little head bobbing on the monitor.
And now here we are on Monday.  I kind of had high hopes since he had actually fallen asleep yesterday.  But per my mom's advice, I even gave him some Tylenol about an hour before his nap just to take the possibility of teeth hurting (he is getting 2 molars in, BUT has been in good spirits the rest of the day so I was already leaning towards the fact that his teeth were not to blame for this nonsense!).  But as soon as I said the word "nap," he started crying and didn't stop for
Colton takes a nap at the same time Levi does, so it's not that he wants to hang out. And I've even made a point of putting Colton down first for the past few days.
I've tried keeping the house absolutely silent.  I've tried having the tv on.
I've thought that maybe he is trying to transition to only one nap.  But on the first day of this, he didn't take a morning nap either and it didn't seem to help.
I would never leave him crying if I thought for a second anything physically was bothering him.  Like I said, he is most likely getting in some molars, BUT they don't seem to effect him the rest of the day.  Plus, I gave him the Tylenol today and we really didn't have any better results.  This seems to be a battle of the wills we're fighting and gosh darn it, I'm going to win!
I am at a loss you guys.  I feel awful letting him cry that long, but I don't know what else I can do!  He is just barely over a year...there's no way he has outgrown his nap, right?  Could it be some form of separation anxiety (although he still goes to the babysitters at the gym with no hesitation)?
Nothing else has changed about his daily routine...he's eating and drinking as much as ever, activity level is the same, and except for Saturday's debacle, he's taken his morning snooze (about 15-30 minutes) both Sunday and Monday in the car.
Luckily, this does not seem to be effecting his night time sleep either (partly because I've been having to wake him up after only napping for 45 minutes or so because he isn't falling asleep until so late in the afternoon), which has me even more stumped because we do the exact same thing then that we do at nap! Maybe all of a sudden it's no longer dark enough in his room at nap?
 I need help...please!  Anyone!  Even if you have no kids...anyone's input is appreciated!