Looking For Help, Hope And Understanding

It has been almost 1yr since I found out a friend of mine is a heroin addict. At the time he was clean and had been for @ 8months having just come out of the most recent of many programs he had been in over the last several years. I had only seen the effects of this drug once in my life and from a fair distance so I was not familiar. I just knew that what I had seen this one time was the saddest, ugliest thing I had ever seen in my life. So when my friend told me I cried. It didn't change my friendship to him in the least, however. We just continued on. This was in October (my birthday to be exact) of 2003.
In mid December he e-mailed me at work that he had a real depressive spirit overcome him after I had left his house the night before. This is when he began back on that downward spiral. At the time I did not know it, I just knew that there was something wrong and it kept getting worse. He was changing, becoming more and more withdrawn, angry, hurtful, etc. This is when he began to "borrow" money.
As I said before I had no knowledge or understanding of anything having to do with this drug or the addiction. I have always been a fair person and don't like to make accusations without knowing what I am talking about. I began reading everything I could and talking to everyone I could find that would listen to try and gain some knowledge and understanding as to what I was up against.
I continued to endure his pushing me away and kept coming back as strong as I could attempting to be encouraging and expressing my love and concern. I finally told him in late January that I knew, he denied it and got angry with me. I decided to give him @ 2weeks to come clean with me. I knew that one of his biggest fears was for his parents to find out but, I knew that I could not continue with this knowledge, stand back and watch him kill himself. He is so much better than this drug.
Early February he did. He had begun the 21 day detox at the methadone clinic. He needed my help he couldn't afford to pay the program. Detox failed before it was completed.
I encouraged the maintainance program as I prefered this over him shooting up. He agreed and has been on it since March of this year. He continued to use. Sometime in May he began not using for a bit. He moved in with me in June (as he had used his way out of his apartment).
He remained clean for awhile (or maybe only chipping so not as obvious). He began to lie and steal again. He had always said to me that this is something he has to go through on his own. He needed to do it his way. I let him because I knew that if I pushed to hard I would not be able to be there for him at all.
Last week, I smelled something in my house, (guess) I debated as to what to do. I myself started to feel funny and got scared (I have never used heroin) I went into the room to find him past out with his little goods by his side. I made the terrible mistake of staying in the room and had a horrible reaction to my exposure. I was horrified. This was it. I have a 5 year old who sleeps in the room next to him and she could not be exposed to this and I have no desire myself to be high or ever experience what I did again.
I told him that it was time, that his way does not work and it is time to make a change. If he really wants to be free of this demon something has got to give. I have put up with the lying, the stealing, the emotional abuse and supported him financially giving my trust when not really justified for far too long. I need him to be accountable to me. I will help him beat this thing but, he has to fight.
I apologize for my rambling I was looking for some stories of hope the other night as I know he is not willing to go back into a program at this time. (I think it is possible for him to do it without, provided the necessary support system is in place). Anyway I stumbled upon this site and I read and cried and cried and read some more. It is so heartbreaking the effects this demon has on everyone involved. I am interested in any advice I can get. I am curious about the different drugs I have been reading about that are used instead of methadone. (Sub, Naltrexone?, etc.)

Thank you
Jen
How about if I ask specific questions?

Is there anyone here or does anyone here know or know of anyone that has been successful in overcoming heroin addiction long term (life long even)? Is that a realistic goal to set? Realistic expectation?

I would like to understand "triggers".

If I think of more specifics I will post, I guess.