iPhone wont let me load up apps, itunes wants to restore it... HELP!

Hi,
Basically, ive been using my iphone without a fault and all of a sudden for some odd reason the apps wouldnt load up. I had this problem before and to solve the problem all i had to do was connect it to itunes and the problem went away. However, this time, itunes isnt recognising the iphone and is saying that i need to restore it to factory reset. iTunes also seems to remember my music and films but none of my apps. Ive spent alot of money on these apps and now i cant find them in itunes, and now they wont load up! Im reluctant to do a restet because i dont know if i will lose all my apps and have to buy them all over again. It all started off when i turned off the iphone becuase it ws running low on battery, so when i went to turn it on again (this is without charging it) it was stuck on the screen with the apple, so i managed to turn it off, then when i turned it on again, it would load any apps...Any thoughts, answers or suggestions...i need help from someone who knows about this stuff, becuase im new to apple and im very confused...Thanks,
Josh