MY iphone is jailbroken and its in a constant restart/reboot.how do i fix this?

It has the apple "apple" logo on screen and it wont go away, i've reset it by holding down the sleep and home button at the same time.nothing happening. I havn't upgraded to the new 6.1.3 for iphone yet, im downloading it through itunes now. Will that help? I have my iPhone backed up on my computer but it wont reset from back up saying an "error has occurred" it doesnt say what error, what should i do to use my iphone? Jailbroken or not

You should probably go and speek to apple and in my opinion it is best to not have it jailbroken:)

Stop jail breaking you phone