Deception goes hand n hand with addiction. Building trust with an active addict is near impossible.
I think it all begins with you and how you feel about his lying and his drug use. Do you feel he is a drug addict or do you feel he just uses cocaine and meth on and off? Because at this point in time it all depends on what you are willing to truly see and accept.
I for one do not believe that he didn’t know it was crystal meth and not cocaine. Someone who’s been a regular cocaine user for 5 plus years knows the difference. But it’s really about what you are ready to accept or not accept yet.
Learn as much as you can about addiction, about addict behavior, maybe see if you can find an nar-anon or al-anon meeting in your area and moving forward take things slow don’t rush into anything or make any major decisions, allow yourself time to figure it all out.