You say you updated the phone, and then say you are rooted. So does this mean you rooted and then accepted an over the air update? If so, that's your problem: the OTA update is a patch that's designed for unmodified software, and rooting modifies it. Hence the results of applying a stock update to a rooted phone are unpredictable, but rarely good.
So, firstly have you tried forcing it to shut down (press and hold power button until it restarts)? If you are lucky and installed a custom recovery it probably hasn't been able to apply the update, in which case you should just be able to restart the phone.
If you still have a stock recovery it would have installed the update. In that case you may have to reinstall the phone software completely using a ROM Update Utility (RUU). If so let us know what OS version you had, what country, whether you bought it through a mobile carrier (who would probably modify the software) and if so which one, as we'll need that to find an RUU (or if you know how to use fastboot, "fastboot get around all" and tell us the cidnum).