I am the son of heroin addict. He died two years ago but that doesn't change how he affected my life and myself deeply... He shaped me into what I am today, a person with deep scars and trust issues, also addicted to adderall or ritalin. I have plenty of family that is alive, but only one person that is willing to talk to me like a decent human being...but family doesn't have to be only blood relatives.. Do you not consider your MIL to be family? I consider my former foster parents (who I've only known for two years) to be family...hell they are my family, I don't know what I'd do with out them.
Honestly, my suggestion would be to stay away from him. If he can't support you and is in his own addiction himself, then he's not going to be a good influence on your recovery and will only provide you with more excuses to use. If you don't want to cut him out altogether that's completely understandable, but I would still limit my contact with someone who is still using. Take care of you and take a look at the Adult Children of Alcoholics (or substance abusers) section on SR, you'll find a lot of good info there
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