We've hit yet another snag in sleep.

Lately Matthew has gotten over being sick and also is waking around 7:00 a.m. rather than 6:30ish. That's fine and dandy, but now he is trying to refuse to take a nap. He normally seems a little sleepy around 10:00, but that is too early, so we push through, have lunch and I usually lay him down around 11:30-12:00. Normally we either read books or I let him nurse beforehand, then he goes down awake and plays for awhile, then puts himself to sleep. Well now he will play for around 30 minutes (or sometimes even up to an hour) and then start crying. I go up and try to calm him, but the crying starts once he goes back in his crib. Yesterday it took me 2.5 hours to get him to go down for a nap, and eventually I wound up nursing him to sleep b/c he was absolutely exhausted but would not lay down. Just kept standing up, rubbing his eyes and crying and carrying on. The today he didn't take a real nap, b/c I nursed him to sleep eventually, but he would wake up and cry each time I laid him down. Then he fell asleep in the car with Dh...around 5:00 p.m. Yikes.
He has also been a little more difficult at bedtime, again, he'll play in his crib for quite a while, then whine/cry a little but finally go to sleep.
I'm not sure what the heck is going on. No way can he be ready to drop his nap. Also, I don't think I will survive if he drops his nap. It's just really getting to me to have to spend so much time and effort trying to get him to sleep. Tomorrow is going to be crazy because he is going to bed super late tonight (b/c of his 20 minute nap in the car), but once things get a tad more normal I was thinking maybe trying to put him down later, like 1:00 p.m.? But then if he takes 30 minutes to fall asleep, he won't be getting up till 3:00 p.m. and then maybe not tired for bedtime? I have been doing bedtime a bit earlier, around 7:30 p.m. though sometimes it can be more around 8:00 p.m.
Is there something about this age maybe? Please tell me this is another phase and he will go back to taking a nap without hysterics? I'm not opposed to CIO, but he gets himself so worked up that he can't calm himself down so I don't think it's going to work for naps. I'm just at a loss for why all of a sudden he is fighting it SO much. It's not like naptime is some new concept.