I am so please that you have found your way here, and have shared your story and your feelings, it is not easy to post for the first time, let alone when you don't know what to expect, so well done for reaching out for some support and some comfort here.
You mention that you as you are younger your issues are not really valid, you could not be further from the truth. You are so valid and in fact if you can get some help and guidance and support while you are younger, boy it makes for a fuller life, you have managed the feelings and emotions when you were young and not let them develop into bigger uglier things in your adult life. I am really proud of you for seeking some support.
I am so very sorry that you have been feeling so very bad in the past that it lead you to self harm and to suicide ideation, the pain that you must be going through to feel the need to release it like that horrific. I am also saddened to hear that your family are abusive to you, has this improved since your hospital stay or is life back to "normal"? Don't feel you have to answer that, only if you feel comfortable but I just want to ensure you are not only safe from yourself, you said you are, but safe from your family too.
Being young these days is so much pressure and so different from my school days. There is pressure to know what you want to do, to do well in school, technology has changed everything from the way we connect, or lack there of and the way friendships are formed and maintained. I am so sorry you are struggling with making some real connections with friends and that you feel like you are on a rotation of people trying to find your "crew". Please don't lose the will to try though, it does take time to find our people and the thing is that school is tough and everyone, I believe is also struggling to fit in and be accepted, which leads to them not truly making connections either, or being true to themselves.
I feel like I am waffling here but I think you get my point. You will find your people, do not give up hope. It just may be outside of school or through a hobby or interest that you do. I think if you can focus on some things that make you feel good, give you joy and try to regain focus at school, make a happy version of you, you will find your people.
Hope to chat to you some more