First of all you're not a bad person in the slightest, you're one of the kindest people I've met, don't think that about yourself

Maybe he's distanced himself because the thought of you reminds him of your mother. It's quite a strange situation really, I don't have contact with my dad either however I'm glad because I dislike him after what he did to my mum.

From comparing our situations I'd say that with your mum passing its only natural to want a connection with your dad, if I was in the same position as you are I would desperately want to have a relationship with him. Having only one parent must be quite hard, especially when the one you do have is acting the way your dad is.

Whats you're current living situation like now? Do you have any kids? Despite hating my dad I still have an emptiness left inside of me, its hard to replace the hole that a parent leaves. Even though I don't have kids yet, I have a very good feeling about trying to be there for my kids if I do have some or just being there for people close to me in general.

I don't think you're ignorant or anything at all, you're reacting to this situation just how I and I imagine many people would