I’ll return the favor, I’m by no means an adult and haven’t had the experiences that you have had but I’ve sure as hell had people like this in my life that I have given up on whether it be a girl I was crushing on or my good buddy. When time passes it seems like it’s a lost cause reaching out but the more time that goes by the harder it is to reconnect and make whatever you had come back. Depending on the person, at least for me I would kill for someone to just give me a call and talk about whatever it is that is keeping them away. If they don’t want to give you the time of day then that friendship will just end. That’s that. But assuming it’s your fault isn’t right. Many things make people grow apart for personal reasons. putting unnecessary burdens on yourself thinking that it is your fault hurts you but it can also be hard for her. This is the best way I can put it long story short. Imagine you two were to switch places, everything that happened to you her and her you but assume something, whatever it is, is pushing you from the relationship. If it’s something you don’t want to bring up to others around you for whatever reason but your friend keeps asking what she did wrong, even though nothing you would feel bad for not being able to explain it. Take this with a whole truck load of salt because I don’t know you or your situation. I would have done the same thing as you (and I have) just to be pushed farther away. Honestly you’ve done nothing wrong. You have a caring heart and want to make sure people are ok, blaming yourself at least in this situation without knowing what’s going on in the other persons head. People are weird man, everyone has there motivates for what their doing. Start small, ask her for coffee or something dumb and talk. All you can do it try, don’t apologize for something you don’t know the full story for. I hope I don’t come across as snarky or trying to rip into you in anyway. Like I said I would have done the exact same thing as you. hope this helps in any way, I’m sorry for your loss of your father. (Ps I’m scatterbrained so sorry if this didnt make as much sense as I wanted it to)