My LO is almost 15 weeks and his naps have gone to crap the last few days. He is so tired and he absolutely won't sleep!

A few weeks ago we started a nap routine and it was working beautifully. Swaddle, shut curtains, turn on white noise, rock to sleep. He would only sleep 30 min (occasionally more) but we were putting him down for a nap after an hour of him being awake. The last few days, though, we just start to swaddle him and he starts fighting and screaming. And fights and fights and fights sleep. I just spent an hour rocking him and he got to the point of fighting to keep his eyes open and he just won't let go and fall asleep. After an hour I just put him in his crib and walked out because I couldn't take it anymore. He is in there talking and laughing at his mobile (that's not even on) and acting like he's not tired (but I know he is!!). What do I do?!? (I watch closely for tired signs and take him upstairs the moment I see one). Please help me not go crazy! I didn't think I was ready for CIO but suddenly that's all I can think of to do!

PS his night sleep has gone to crap too. He'll fall asleep ok but last night he woke up every hour from 11 until we got up at 730.