karen:
I am so sorry that you are going through this mess. I was engaged in past. We dated for 3 years and were engaged for 9 months before I called it off. He also had an addiction: alcohol. I started finding out about lies and things he was keeping from me. I am in so much debt b/c of him. I loved him so much and I wanted to make things work. He started therapy and things got better. I moved to GA before him to get things going and it was horrible. I still didn't trust him (and I was right not to). I found out he had lied to me about work and other things basically the whole time I was in GA. I finally called things off (1 month before the wedding). Everything was booked. I had my dress, people were coming from out of the country. I had a lot of guilty feelings not only b/c of our guests, but b/c of my parents (who had paid for everything up to this point). My parents were VERY supportive when I told them I couldn't go through with it. It was the hardest thing I've ever, ever had to do and it took a loooonnng time to get over all of it; the disappointment, lying, trust issues, etc. BUT it is the BEST decision I could have made!!!
To sum up (lol) He has to completely work through his addiction before he can be a good partner, the type of husband you deserve. After my failed engagement I live by this motto: I'd rather be alone than in bad company.
Good luck honey. Please, please, please think this through very very well. If that little voice in your head says walk away, you need to do it.