if the removing the sim card trick didnt work, you probably are best to just hard reset it. Learn from this, overclocking the phone, as with any overclocking, should be done in increments until a safe overclock is achieved. Now you know why.
"Son, no one gives a #### about all the things your cell phone does. You didn't invent it, you just bought it. Anybody can do that." -Dad
-G1 Early adopter
-Nexus with 3G issues
-Droid Incredible. Finally, a phone that works.
-Thunderbolt. Now waiting for the 4G to work correctly