Sometimes some people's lives just suck monkey balls and your sounds that way. I had a similiar start. Parent who did not give two fucks about me, money being the most important thing in people's lives, and where is this thing called god to help you out from time to time (and fails to deliver).
All I can say is there is no god and all religion is false and an invention of man to control the weak minded sheep.
It is tragic what happened to your girlfriend, but keep going is all you can do. That is what I did. Life is still not all great and my wife and I are still having problems. All we all can do is keep going.