Struggling with Sleep and Depression After Abusive Relationship and Loss of Father

Hey! my name's Noah, I'm 21 years old. recently I've been struggling a lot with going to sleep and on top of that I suffer from depression, so some nights I'm honestly up crying about something, I've felt immensely stressed because I just got out of a 2 year relationship that was abusive and I also lost my dad in June. so I have this problem of over thinking things like if I'm going to die in my sleep, or if I'm doing good as a young adult. Im also struggling with being alone so suddenly, I got used to having someone here I could talk to and things, when she tried to be nice she was more than loving to me. she suffered from BD and is Schizophrenic and never took any meds for it so the smallest things made her mad. so because of those moments where she was amazing I'm not used to this, she left suddenly because she realized she needs to work on herself before she keeps being in any relationship so that way she can learn to love herself to easily love someone else, she did love me yes but couldn't show it because she never had the energy apparently due to how she looked at herself, so I didn't put up a fight when she wanted to break up..it just felt like I lost a huge part of my life, in February I suffered from DKA and was in ICU for a week due to my abuse on my diabetes, and she was there for me every step of the way, I remember waking back up in the hospital and the moment she saw me wake up she bawled, and from that moment it reminded she loved me more than anything else, she just had her own demons as did I. as for the constant fear of death..I love life, the things I currently have in life, I play guitar and I am in a band, and I have a dog named Milo that means more to me than anything in the whole universe, entertainment such as a game console and laptop, a tv. and I'm glad I'm at where I am now as in 2019 i was homeless under a bridge for 4 months, and I've been trying to get better in life since. when I had my incident in Feb this year ever since I have been in constant fear of dying in my sleep..I don't want any of this to end anytime soon, I love my family too much and my dog and the friends I have to go out like that at a young age, I'm sorry if I seem like I'm over reacting. and if not it would be amazing to just sit and vent to someone about all of this and other things, as well as receive advice from those who've been through what I have or similar!