<human>: Can you condense the text into a few key points?

This is my first real post, I apologize for errors. I have been with my SO [23M] for six years. We have had our share of fights and disagreements but he is my best friend. About three years in, I heard through mutual friends that he had been smoking pain pills while attending a Pharmacy Tech course. As a girl who has had drugs affect loved ones before, I always vowed to myself I would never touch them. My views have never changed and my SO is fully aware.

After this his parents put him into rehab meetings and he would be put on Suboxone. He would go through periods of time being clean, but after three months or so he would startup again. After what I thought was a great time in our lives, I find out of a serious heroin addiction. He is currently"getting clean", yet again, and is attending a 40hr a week therapy. Yesterday was his first real day and when he came to see me for a bike ride, my heart sank because his eyes were low and he was a zombie. I am almost certain he had used. 

My question is if Suboxone has anything to do with it? I know it's an opiate, but he often tells me he looks like he used but "its just my Suboxone". I feel silly eating up any drug facts from him when he knows so much more than I do and I cant help but wonder how often he is just trying to passify me. Please help, I don't want to give up but I have to protect myself too.. Right?
<bot>: my SO [23 M] of six years is a heavy heroin addict. On his first day of treatment he returns looking high again, blames Suboxone. Am I worried for no reason?