Phone refuses to respond to my touch.

My phone will not respond to the touch of my fingers. If I turn it off and let it set for a couple of minutes, I can get a few touches in and then it stops again. This problem started a couple of days ago, then I was notified by Samsung of a software update. After the update was installed, my phone worked fine, until just a few minutes ago and now it's doing the same thing again. I've tried to restart it, but the button won't respond to my touch. Also, and I don't know if this is related or not, a bubble has been appearing at the bottom of my screen then sort of pops and disappears. If anyone could help me with this problem, I would really, really appreciate it. Thank you.