I bought a mouth guard. my jaw pain is gone but i have noticed my bite has changed. if i stop wearing the guard, will my bite return to normal?

Possibly: Can't really tell how exactly your bite has changed or by how much. Store bought appliances although cheap, do not perform like a professionally fabricated night guard. See a local dentist for help with both your bruxism and your bite.

Depends: Depending on the amount of time that you have been wearing the mouthpiece, the bite may or may not return to "normal." If it does, you may want to consider a different type of mouthpiece, not a thick mouth guard that may be shifting and moving the teeth or altering the jaw alignment