Should I restore my iPhone 4? - 1

Lately my iMessages have been taking forever to spend. For example the other night they weren't sending until after 5 minutes. Also when someone makes a phone call to me or me to them, we can't hear each other. I called apple and they said restoring it could help fix the problem. But i'm scared everything on my phone even apps and contacts will be erased. I backed up my iphone to iTunes 11 (the newest one).

If you back up your phone all apps and contacts and pics will be saved and will be on your phone if you restore it

You should be fine if you backed everything up. Have you tried restarting it as well?