Help!!!

Why won' t Lucas take his afternoon nap anymore? I have no clue what I can do, to make him sleep. I know he needs it... He started not sleeping anymore about two weeks ago. He falls asleep in my arms (don't ask me why, because at nighttime he always falls asleep on his own in his bed...). Anyhow, he actually falls asleep in my arms after about ten mintues, the minute I put him down in his crip, he wakes up and starts screaming. So I try to soothe him and bring him back to sleep... he actually falls back asleep but it's the same procedure once I put him down. So I think, maybe I should let him cry for a couple mintues and he'll fall asleep on his own.... wrong thought. He will cry so loud and long, I don't feel good leaving him in there. Sometimes he's so into it, that he sounds he's about to throw up, so I go in there every two minutes or so to calm him down. That game takes about an hour and then I think it's too late now anyhow and he's wide awake again.

I really don't know what happened. I don't know if he's old enough already to skip his naps around daytime. Usually he wakes up around 6.30 am and I would try to put him down again around 12.30 pm and he goes to bed at night around 7 pm. So I thought that was a really good cycle and he was very good with it for a really long time...

I'm still hoping that he might change again and he'll start taking his day nap in a little while. I really need a break of an hour during the day as well and I'm sure it would do him really good as well.