i'm 16 so take my opinion with a grain of salt. I've obviously never been in this situation before but I feel as if you should step back from the both of them. Even though what you did was absolutely horrible I can still empathize that seeing as you're distraught and torn about this. My head tells me that you should get a divorce with your wife. Not going to sugarcoat this or say this just to make you feel like shit but she doesn't deserve what you're doing to her. You've already stated that she's not going to be the one you want a family with so I don't get what's the point on holding on. You should definitely apologize to her SINCERELY as she has been you longtime best friend it seems and there's no one else to blame this but you. There are no excuses for cheating so please don't try to convince yourself any of your actions are justified when apologizing to your wife. As for your girlfriend you two will most likely not last too long together seeing as she has a drug issue and that it bothers you. Including the fact that your relationship came from unfaithfulness I wouldn't see myself trusting the person who cheated on their wife to be with me because next thing I know I could be replaced as well. I think it's better if you just start over from scratch with someone else other than those two. Because again with your wife if you don't see a future with her then there's no reason to rebuild the relationship. And girlfriend of course you could still try for as you do see a future in the two of you, but again being unfaithful, the drugs, etc... It just seems so far fetched to me and that having an honest relationship sounds healthier. This is just a word from a random 16 year old on reddit and other redditors. So do be aware that no one here including me should really take control your life choices. Anyways good luck with life.