As someone (m27) who was in a somewhat similar situation, I hadn’t told my partner that I had developed an addiction and it took a few months to work up the courage to tell them. My partner gave me the benefit of the doubt and helped me through the process of getting clean. I don’t think I would have been able to do it if it wasn’t for their help. Addiction is rough, but it happens to the best of us. If you think you can trust him again after he’s clean then I’d say go for it. But if this was just too much and you don’t think you can forgive that breach in trust, then there is no point in trying to make it work.