I have learned to just accept it and go with the flow. If I get bored and move on, that’s fine. If I never go back to the thing I paid a lot of money for, that’s fine. Making rules about these things for myself never increased my enjoyment or happiness.
It sounds like you are in a downward spiral. It’s time to pull yourself together and focus on self improvement. Forget about the relationship. Forget about drinking and drugs. If you can raise your self respect and confidence, you won’t fall for another person like this. Good luck!