My iPhone keeps restoring and won't sync.

I've had my iPhone for more than 4 months and it has worked perfectly until last week. I updated to the latest iTunes version and since then whenever I try to sync my iPhone it says I have to restore it. I restore it and then it would sync until yesterday. Yesterday after it restored instead of syncing it made me restore again. I went along with it but then it does the same thing. As soon as it's done restoring it just wants to restore again. I decided to give up on syncing it for the time being. Then when I went to open an app the app closes about 1 second later. This happens with all apps except for the basic ones included on the phone(phone, camera, photos, safari, map, etc.). I'd appreciate any help.