Help W/ Iphone Loop

Ok, so the other day, as i was getting out of my car, i dropped my iphone, and it left a dent in the top right side of the backing. I thought everything was fine, but when i got home, i turned it on, and it went in to a cycle about every 5 sec, what happens is, the apple logo appears, and then reboots and does the same thing constantly. I finally got it to boot, but then it started over.

Any suggestions would be appreciated,

also, the phone is jailbroken, so i cant bring it in to the apple store.