Artchic, you aren't a lost cause. What you are is depressed, and depression makes us think negatively and in a confused way. It is a struggle that many know all about, but the good news is you clearly know that is your problem because you are posting on a depression forum. Good for you, understanding the problem is key to fixing it.

I agree that your first step should be to concentrate on yourself. The right relationship would be great and you like everyone are worthy of love and intimacy but you can't expect someone to fix you. It seems like your family is pretty disfunctional, I agree it should be your aim to move out and get your independence but I know that seems hard right now, and I think a job would really help your esteem and options and a whole lot more. All that will come in time, fixing your depressed state of mind comes first.

So how do you do that? Well that's the question of this forum, and there is a lot of support on how to do it. As to which option will work for you, meds, herbal remedies, therapy, nutrition, exercise, a combination of some or all, I don't know. But start small, maybe go for a gentle jog and cook yourself a healthy meal, then look for a therapist that does online sessions. That might make you feel just a tiny bit better and more hopeful.

Good luck