What a terrible time for you, cf. So much crisis and shock to absorb all at once. I wouldn't be surprised if you don't have some physical symptoms in the weeks to come....free-floating anxiety or racing heart or nausea. If you do, know that it is the body reacting post-trauma. If it occurs too long and is severe, please see a doctor.
He is a heroin addict, sweetie. I love a heroin addict and have not seen nor heard from him for three years. Mine is a kind man, a good father, a hard worker, and to this day, still the love of my life.
He had 10 years of such good, strong 12 step recovery. Then some things happened in his life and he relapsed. So many lies, after that. I never believed this would happen to him. And I was nauseous every day for two years after he went away. The shock.
Your fiance is very very sick, and I believe that even 45 days rehab may not be enough for him. Heroin is a snake that winds its way through every cell and organ of the body and does not let go. He will need such intensive rehabilitation to have a chance. He needs the longest rehab and sober living and IOP he can get. He has two years, at least, of living on a very thin wire.
I believe your relationship with him should go dormant for awhile, as a bear hibernates and stores energy. I believe you should tell him you love him and that he is very sick and that because you love him, you are going to let go and allow him to save his life.
In the meantime, you can attend meetings for yourself, do a year or more of counseling.
If it is God's will that you marry this man, it will happen. But you need to be prepared. You cannot possibly marry a heroin addict until you yourself have been immersed in recovery and you understand the demon which will shadow you both.
The Craig Nakken book mentioned above is excellent. As is his other book, "The Addictive Personality." Two of my very favorites. I have read the latter probably twenty times. Kept having to replace my copy because of so many underlinings and margin notes.
Welcome to this forum. You now are a member: Friends and Family of Substance Abusers and Alcoholics. This is your reality. No amount of wishful thinking will ever change that. You have found yourself on a path you did not choose....but it is yours now. I hope you will recognize how serious this is.
I need to believe in recovery. I need to believe in the miracle of the 12 Steps of AA, which are said to transform disintegrated persons into beacons of light.
I hope this will be so for the man you love (and occasionally want to murder).
Again, welcome.
Bluejay