There's a lot of negative self talk in your post.

You're not the first person to find themselves involved with someone with addiction struggles. It's rather common to have something or someone from one's past that affects future. Couldn't save sister, now determined to do better and be there to save your husband.

It's not shameful to seek counseling. It'll help you feel a lot less chaotic in life. Words get said when others use/misuse/abuse that unless grounded, will wound worse than anything. It's not just the non sober moments, it's as the substance clears out of the system, that fine moment between being sober and being straight. Never mind what other physical and psychological effects that the substance drudges up.
There's a saying, I'll only leave, when I can no longer stay. Sort through this stress and then decide on a clear conscience. Have a safety plan if it gets physical. Don't believe that the next person couldn't bring their own garbage. Learn you, then life will be ok.