Hi phoenixwaitingtorise
A warm welcome to you and I'm glad you came here. Something has led you to seek resources other than your friend. Perhaps you can reassure your friend that you're trying to manage your mental health challenges by accessing the forums here. I imagine it will please them to know you have people besides them to chat with, as they feel like they're letting your down while they're taking a breather. Perhaps once you reconnect with them, they may be surprised by a few new perspectives you've picked up here.
I feel for you so much, having been raised (or should I say brought down) by a mentally and physically abusive person, especially one who believed they had the right to be this way. Such a person may easily say 'Well that's the way I was raised and it didn't do me any harm'. I beg to differ. You could say it made them emotionally numb. You could say it led them to not care for reason, the reasons their child has for what they do or what they say. You could say it led them to believe physical brutality is the solution, over teaching their child constructive skill sets. So, at the end of the day you could say, overall, it did do harm. It led that person/parent to be emotionally disconnected, careless, unreasonable and unskilled in the way of life and parenting. Since you are looking for greater understanding, you could say you are more emotionally connected, careful, reasonable (seeking to find reason and understanding) and you are in the process of skill development in the way of life. Good for you. It takes a conscious person to embark on such a quest, a quest your father never took.
The problem with that 'Toughen up' mantra so many parents can tend to instill in their child is it does the opposite of making us sensitive enough to find the detail and the answers as to why we and others tick the way we or they do. Wondering whether you dad was one of those 'Toughen up' people. Toughening up tends to shut us down to some degree. So, I'd like to think you're sensitive when it comes to your quest for answers and self understanding in life.
Again, glad you came here, a place with so many amazing sensitive supportive people :)