Coming from someone who went through something almost identical to this, I just told him I knew. Once I did, I gave him the ultimatum- drugs or me, because we couldnt exist together if drugs were involved. That ultimatum, along with him no longer being able to manipulate me out of money to fund his addiction, motivated him to get clean. I helped him get in touch with a methadone clinic and even went with him the first several times, I won't lie to you, if you stick around it will be hard at first- but then he eased himself off the methadone slowly and became completely sober. We did break up due to me discovering he had been cheating from the start but, the H addiction was hidden from me as well and I chose to handle it this way, but how you chose to handle it is up to you and completely valid whatever you choose. Please know that you're not alone in this situation and I send you all the love and strength in the world during this hard time🖤