You have absolutely no obligation, whatsoever, to ever contact either of your parents. You are a free person, you are totally free to cut ties, and you surely have loads of reasons to do so, probably really great reasons too.
I have been no-contact with my father for 9 or so years now. I refuse to contact him, ever. He has wanted contact with me, and I still refuse. I know he's hurting because neither of his kids wants anything to do with him and refuses to contact him. Tough shit, too bad. Sucks to be him, f*ckin' loser. Maybe he should have not f*cking failed as a parent and just in general been shit, and not there, and not acting like a parent at all, not even a little bit.
I know the guilt feelings related to cutting contact with a parent. I've been there myself. Every now and then, I will have a day where I feel it again, but all I have to do is talk to my mother and she makes me go back to feeling no remorse. It's f*cked up to feel guilt over not contacting a bad parent, but it happens.
Over time, it gets a lot easier. You just need some time. Stick to it, you're doing the right thing by not contacting a toxic person.
I quit giving a shit whether he dies, I have moved past the fact that I have no father, essentially. It took time, but I got used to it. I grieved, for sure. I was very hurt. But, I got better. He got in a pretty bad car accident and broke his neck (again), cracked his skull, blah blah blah. It was a real loony toons ordeal actually. His car hit another car (his fault, he was drunk driving), he rolled, and rolled, and the car righted itself, then it went forward and hit a building, and a brick came loose from the top of it, fell down through the moon roof and whacked him in the skull, which compressed his neck, which made one of his vertebrae shatter, because the ones below it had been fused (also from being broken - he fell 3 stories) so it acted like an anvil, and the lack of cushion just made it shatter.
Of course, he's still pretty much fully functional like he was before. Just has his neck held together with metal. I think he might be facing jail time for that, not sure. I don't give a f*ck that he was injured. When my mom told me that, all I said was "jesus f*cking christ what is he a f*cking terminator or something? he just wont f*cking die!"
He's been in so many accidents and stuff. So many times he totally could have died. And every time, he walks away alive. Multiple motorcycle accidents, some car accidents, falling 3 stories.
I have become very callous towards him. It took time to reach this. I just don't care at all about him anymore. It's not like I wish death on him. I am just amazed that he keeps surviving this shit with -relatively- little injury, or bad injuries that heal and wind up not affecting him -too- much. His luck stat is like 9/10 or something.