I don't know how much this applies, but I'll offer it for what its worth.
My husband is not an addict, but we did go through a period where we were having trouble, did counseling and at one point he said he just didn't want to be married anymore.
We divorced amicably but still kept in touch, were friends, and while he saw other people and so did I, the connection was never really broken. We did live together for a short period and split again at which time I told him to come back when he was serious. He did after a year.
The only things that I think might be applicable are - my husband was ready and able to commit to the relationship when he was ready - not before. His behavior spoke more loudly than his words. If I would have had the patience and courage to really see his behavior for what it was I don't know if things would have been different, but at least I wouldn't have been so confused during the time. Love isn't enough to keep a relationship together, maturity, trust, ability to commit and strength of character make it work.
From my experience with my addicted niece, it seems to me that drugs and addiction erode the very things necessary for a love relationship to work.
Best of luck as you try to sort this out for yourself. My only advice - don't be too worried about making mistakes, just keep your eyes open and realize what qualities will make the relationship work and look for good, solid, prolonged evidence of them.
God Bless