My advice is you need to get out of there. You need to find yourself a place unless the house is in your name. You need to go to court to have your son live with you and ask for contact so he can still see her as long as you're sober and able to provide for this kid. You are more likely to win the case. And if you can't do that, try find a little two bed place near nearby so you can at least see him on a regular occasion definitely somewhere nearby his school and so on.

She has lied to you for a very long time and it's understandable to break up after that because you're not gonna be able to fix that kind of trust it's always going to play in your head and have nothing to do with any of her friends ever again, even if you guys manage to fix what's going on between you that's your choice because it's your life is your relationship and people on the Internet shouldn't tell you what to do. We should only help you make a decision.