Firstly(and I'm sorry for the lengthy post), I think right now the people who should be supporting you have sent you the message that they don't care and that because they openly hate you, no one else will ever love you. That because they don't want to be bothered, you are at fault for being a thinking, feeling, needing human being. Whether you realize it or not, I think you've absorbed that message and started believing it. It isn't true. The possibility for friendship and love is there for you as much as it is for anyone else.
The people who hurt you try to tear you down and conquer you for their own purposes. Their intent is not to show you your worth, it is to try and assign you the worth they think you should have. Do not believe the people who hurt you. Don't turn to them for comfort when they are the deepest cause of your pain. No one here cares one lick if you are as 'miserable' as you claim to be. We aren't judging you. We've all been judged so much ourselves that we know how that feels. You are free to be you here, free to feel, think and need, just like every other human being who ever walked this earth. PTSD isn't selfish, it's a disorder that you didn't ask for just like you said. Who would?
It would hurt me and others here if you left far more than it would your absentee supporters if you stayed. If it really is a question of who cares, that is the honest truth. They say they don't care, WE DO. And although we are at a keyboard thousands of miles away, we are still human beings with breakable hearts just like you, who have stood in similar places and felt achingly similar emotions. We care and in my opinion, and I apologize for the bluntness, it would be selfish to ignore that.