Aw that’s a very sad story and one we can all identify with. This life is like death of a thousand cuts. Little by little we lose ourselves. The whole family needs help and support to recover from addiction.
Are you still separated? Have you got support from friends or family? I hope so. If not you can get help on here and also from the Icarus Trust. It sounds like your partner is very deeply caught up in his addiction and unfortunately it means that his behaviour is not his true self. The drugs have basically hijacked his brain. That doesn’t mean it hurts any less, but it isn’t any mark on you. Just a horrible and tragic situation that you and your poor kids need to heal from.
Sending you love and hugs, as there but the grace of god go all of us. We all know your pain xx