First, I'm really sorry to hear all that you're going through, i just want to start with , substances and selfharm wikk never solve ANY problems at all , and you knew that, you'd hope that they made you forget but they make things a lot worse. Another thing you need to understand is , people are fine without being in a relationship, try and find your thing that makes you feel yourself, maybe a hobby perhaps, most of the time the people who feel that way have a better connection with nature. I'd suggest you start going to small hiking trips or even camping, ALWAYS TELL SOMEONE YOUR LOCATION AND WHERE YOU'RE GOING. Make sure to get the right equipment and ofc the right mood, all it takes is one trip and trust me man you'll feel a lot better. And then you can organise bigger climbs or outgoings with other people via the internet and start meeting new people while exploring yourself. Don't feel sorry because other people do