Hi Iggy. 34 is a nice age, so many great things you can do and experience.
Would be nice to know how your mind works 🧐 but let me attempt to break things down for you (and sorry if you don't find some of them pleasant).
First, I guess you understand that your parents' divorce (especially if it wasn't a calm one) didn't help much your upbringing and your mind developed in a way different to that of a happy kid with both parents caring for him.
Still, it's ok, it happens a lot and people do cope with the consequences.
Then the traumatic event of your mother dying when your psychi was vulnerable and immature at 17 - didn't help at all. Both events weren't your fault, but just a big misfortune. To tell you more, your dad's poor attitude isn't your fault either and partially not even his. What you wrote about him says that his upbringing wasn't great either, his brain/mind don't function in a healthy fatherly way. He sounds like a damaged person. And it's not your job to analyze his behaviour and try and fix his psychi. Have some forgiveness instead. Your dad's brain is wired the way his parents and environment raised him, he can do just as much, which in his case is nothing.
Now think about your friend. First, he is not a flawless person either. No one is and you should not expect people being forever there for you.
Second, he is the only mate - that's a trouble. People want good emotions from friendship, and if you keep saying negative things, they leave regardless who is right. Because he is not your parent or relative or psychotherapist and is not obliged to satisfy your demands. The amount of positive emotions you bring to your friends (and they bring to you) should always be much bigger than negative ones. Maybe he just didn't match your personality and you just need to find friends who would. And not ONLY one friend. Aim for a dozen.
Your friend forgot good things simply because on his inner scales the bad things you told him outweighed the good ones.. and your relationship became poisonous for him.
You need to understand that we are all imperfect humans wanting appreciation, warmth, respect and easy and positive relationship. As soon as you start giving that to people around you, you'll become magnet for friends, girlfriends and good job. Simple as that.
No complaints, nagging or phrases like: 'no one understands me' would draw mentally healthy adequate people to you.. unless they are psychotherapists.
You would have to change the way you think and talk to get the life you want. Take responsibilities and say goodbye to that troubled 17 years old teenager inside you and give way to the 34 years old adult man.
