Some mornings I wake up and the left side of my tongue is numb for 3 or 4 days.. then its OK for awhile, then I wake up and the right front quarter is numb. Could I be biting it at night or is there another answer?

Really not sure. I would see a doctor about this, there's no way to even guess online.

Before I even finished reading your question, I thought that maybe you are biting it or pressing it up against your teeth for a long period while you sleep. I am not a doctor though. Since it's been happening consistently, I agree it won't hurt to just get it checked out.