Fear of opening up to others, and feelings of self-loathing

It's true that your logical/rational brain knows what happened to your father was not your fault. Your hurt part that most definitely goes way back for you doesn't deserve to be "self loathed". Shame and guilt are part of human grief ((Mr. Walker)) you are an emotional being and human beings feel shame and grief because human beings WANT to find a way to help/fix/and contribute to our survival. However, Mr. Walker, you need to also learn to accept the fact also emotionally that there was really nothing you could do and even if you were with him when he had a heart attack there most likely would have been nothing you could have done to save him as often even when people try to help nothing works, it's a fact. Often by the time someone who was an alcoholic for many years experiences a heart attack often that is because other organs are failing like the liver etc. which is often what is badly affected by the disease of alcoholism.

It's time to accept that there really was nothing you could do. Also, things got to a point where you needed to leave and get away from the abuse you experienced. Yes, a lot of alcoholics can nice and functional at times but also toxic and abusive and have this Dr. Jeckle and Mr. Hyde in them. It's a very selfish and self absorbed disease.