lately, i've been biting my gums alot and causing sores. Could this be from a change in my bite? it feels like my lower teeth have shifted to the front more. I have had 2 teeth removed on the bottom. Does anyone else have this problem?

I have the same exact problem.

I recently had 3 partial crowns done and one inlay.
When the prosthodontist went from doing the crowns on my right to the left, the left ones felt lower. He added more material to a top tooth but they still are too short. They are permanents so he refused to replace them.

Bottom line is biting gums means there some tooth structure missing so instead of the teeth fitting into each other they hit gum instead(the teeth may be shifting). My prosthodontist said that my jaw was moving forward also which I don't think is a good sign. He said a possible solution would be to do more inlays and bonding to "build up" my 2nd molars some more. But I don't trust him as when he did the previous onlays, he said this would "build things" up, but something went wrong and they came out shorter unfortunately.

Do you clench your teeth. I find if I keep my jaw very loose(lips together, teeth apart), I keep the teeth from hitting the gums. But with me, I know things are really messed up.