How old are you, OP? What kind of interests do you have? You've not mentioned anything physical such as a disability so pardon me if I'm wrong in any suggestions.
Obviously, joining groups won't be a magical solution, but they're often a good way of meeting people (and potential partners). Places I've met friends and partners, outside of education and work related events:
Fencing
Jewellery making/glassworks classes
Art classes
Gallery events/exhibition openings
Choir practice
Book clubs
Archery
Obviously these are all to my tastes, I don't know yours. But the rule of thumb I've found is that there's usually something somewhere if there's an interest. And, to be honest, a good few of them I didn't think I'd enjoy until I tried it.
It sounds like you've had a rough time of it, but if you'd like to meet someone then putting yourself out there is going to be helpful. In the meantime, are you taking care of yourself? Doing things you like for you? Getting plenty of sleep, eating well, getting some exercise, spending time on any personal hobbies, keeping up on personal grooming? They're all things that can feel a chore when you're low, but do help you feel more human. Loving yourself, or at least liking yourself, is important, and other people can pick up on that sort of thing, too.