I deal with constant over-thinking and feeling bad about myself every day. I constantly worry that the people in my life won't be around for long, which is difficult because they're the first friends I ever really had. I also struggle with a painful longing for a relationship, which is tough because I constantly go through the feeling of 'they will be my reason for living' but that wouldn't be fair to them. 40% of adults in the US are single and half of that number doesn't want to be. I just don't see a point in living anymore, life isn't enjoyable anymore and I'm just so tired of worrying about something all the time.
My dad took his life 10 years ago and my psych has chalked most of my day-to-day issues up to my grief surrounding that. His leaving has made me subconsciously feel that I am never enough. I don't know if I have it in me to get better, especially when there's no guarantee I'll ever truly get better. This also makes it harder to justify death because my mum has already had to go through it once, how can I do it to her again?
I just don't know where to go from here. Part of me doesn't want to die and I'm getting to the point where I hate that part of me. I just want life to not be such a struggle.
I've done a lot of the same things as you before. The fact you call your overthinking exactly that tells me you are self-aware it's putting too much thought into things. Where you are seeing things you did as wrong or stupid or embarrassing, chances are 9 timed out of 10 nobody else thought that, it was only you giving yourself a hard time.
It's natural to worry about losing people we care about, but you shouldn't let that depress you. Make more memories together. The ones that do leave for no reason, if that happens, you'll know can't have done it because of anything to do with you. I really struggled with this one. I've lost so many I can't count. As much as it hurts, it has also had a way of making the ones that have lasted more precious to me, made my friendship with them deeper because of the loyalty they've shown. I think this can happen for you too.
And I get that longing for a relationship more than you could know. I've made…very self-destructive decisions in the past out of desperation for exactly that. In hindsight, I realize I was struggling with a sense that my life lacked value without someone having chosen me to be with. But gold and jewels that haven't been found yet don't lack value, their value is there wherever they are out there in the world. It's the same with me - still single for now for the record - and same for you too. You have a value intrinsic to you. Just because someone hasn't found you yet that is a good fit doesn't mean that nobody will. Shit like this takes ages for some of us…but imagine how sweet it will taste when we find it.
I'm really sorry about what happened with your dad. I doubt your psych is entirely wrong there: they are oversimplifying things maybe but this has to have a far reaching impact on you. Can't say anything that fixes that. Something I feel like you should give some thought is how you said that happening made you feel like you are never enough…and also worried about your mom if you CTB because she had to go through with this before. Did it occur to you your mom has your exact feelings? Your dad chose her and still did that. Even if she doesn't say so, I bet you she has at least as bad if not even a worse of a case of feeling like she isn't good enough if that she lived him and gave him a relationship and still couldn't make him happy enough. So if you go, it's not an if I think: she will be devastated. Could potentially encourage her to do the same, if she already struggled with thoughts like that she hasn't expressed to you. Just to be clear, this isn't me being pro-life. If you think things through thoroughly and decide leaving is necessary I'll respect it. I'm just stating the facts as I see them about the situation and that's how that looks to me. So something to consider carefully if you care about what happens to her.
In general, it seems like you are dealing with some indecisiveness. If that is true, don't make a final choice yet. Take time, think, and while you wait, try to do what you can to make day to day life better to deal with. Lean into your hobbies more. Hang out with friends even more if you can. Do what makes you feel at peace. While you are here, no reason to struggle more than necessary if you do have some power to affect things. I'm pulling for you, either to get better or find the conviction you need. One way or another taking time and not rushing anything sounds like it will be best for you whatever that outcome. I'm really pulling for you.