i had a nagging situation as well
This summer I lived with my aunt for part of it. She was always up in my business trying to "help" but she was a real friggen thorn in my side. So one day I got my friend packed the truck and moved out in front of everyone. They were stunned but i did what i needed to do. My point being, if you dont want to be in a particular situation, dont be. If youre worried about getting tail, or burning bridges- you need to know that your own well being comes first and at the expense of nobody. Your g/f sounds like a real donkeypunch if she cant handle that you dont want to drive around her mom or whomever. If thats the case you need to dump her ace and move on regardless.
By the way- keep searching for jobs keep your nose to the grindstone Im sure youll do fine as long as you keep showing up