Pughead, I totally understand your anger/grief because I was married to an abusive man and before I finally left I began having fantasies of tieing him to a chair and lighting him on fire with gasoline. Just a fantasy I never did anything to hurt him physically.
Severe unrelenting stress from a partner can cause these kinds of desperate feelings. I am betting (and hoping) that what you say about hurting her is only a escapism fantasy. If not then you need to get away if only for long enought to get a grip. Last summer my teen was saying f--- you, f--- you and wouldn't shut up even though I told him to and I had to leave and drive my car for two hours because I was really wanting to beat the living %#@&#! out of him but I knew that would be nonproductive.
Problems have solutions. Do you have a therapist you can talk with? Is your relationship so unstable you should leave? I certainly won't lecture you about drugs and alcohol because I have been there myself but they are only a temporary relief and don't really solve the problem.
Here is a hug from Yoda -