Naptime nightmare

I am having a huge problem with Hugh's naptime. We figured out he had reflux around 6 weeks old and the pediatrician suggested that we utilize our swing to help him be more comfortable. Come to find out, the swing was a miracle worker. It helped him sleep SO well and it was so calming for him. And as a new parent, I was desperate for sleep and the blessed swing gave it to me!

Fast forward 6 months later and Hugh still likes to sleep in his swing, but only for naptime. He puts himself to sleep beautifully at night in his crib. Naptime, however, is a whole different whale of a problem. He cannot soothe himself to sleep! I keep trying to start him out in his crib and let him cry for 5-10 minutes, check on him and settle him down, leave, he goes nuts again, etc etc. I do this for 30-45 minutes and when it doesn't work (it never does), he goes in his swing so he can get a good rest. I know I need to just pack it away so there's no temptation. I'm not doing him any favors by giving in/up and sticking him in there. But I have no idea what to do! Yes, I've read books, but they didn't work for him for nighttime, so I don't really trust them for naptime! Maybe I'm still too soft, but I just can't let him cry for more than what I'm doing!

I need help! Please give me any advice or details on how your kids learned to nap by themselves. He's thisclose to being too big for the swing and I'm desperate!