Iphone help!!!!!!!!!!!!!!!!!!!!!!!!!!…

so I have an unlocked iphone running on tmobile. It's currently running on 4.0 (which I jailbroke with redsnow then unlocked with ultrasnow). Worked perfectly for about 15 mins but now it constantly restarts on its own and has a message pop up saying "restore needed. iphone cannot make or receive calls. Restore fron iTunes. www.apple.com/support". Wi-fi also doesn't work. Any suggestions?