Shell, I’m so sorry to hear that. It’s doubly hard because you know that, somewhere, the person you love is in there. And the person you trust, the person you would go to when you’re feeling scared and worried and in need of support. Except that’s the very source of all those anxieties. It’s enough to make you feel all alone. But you’re not alone, as you say you do have family who can hopefully help you.
I want to stress that you have nothing to be ashamed of. At all. It will help your well-being so much just to have a relief valve, let alone someone who can support you. And it sounds like you do need support. It doesn’t seem like you’re free to have any kind of life, because you’re as much a slave to his addiction as he is. From my experience, it breeds sadness, resentment, and anger. Do what you can to set boundaries between his use and yourself. I know it’s hard, but in the long term I think sticking it out will hurt even more.