Sweetheart, hurting yourself will release blood and give physical pain; which will later turn into emotional pain, from regret. The painkillers and drinking? That is in the past and tell me what good constantly thinking about it does? Think about it long enough to say what a useless and dangerous thing it was.
Ashamed you let yourself get hurt. I don't remember you saying to anyone at all--please hurt me, I just want to be hurt so I can feel like crap. Of course you didn't. There are some situations that are out of your control, some that are within your control. I know you want out of your house--you financially are not able to do that. Maybe you could write that down as a goal, a reason to push yourself in therapy, to get better to get a good job to afford to move out. I'm not saying you aren't pushing yourself, I'm saying maybe set that as a goal. Be concerned you don't eat anymore, not ashamed. You currently are unable to see through your pain that people do want to get to know you--you have the people at the place you teach, you have the people in your class, there were people in the table-tennis group...None of them didn't want to know you. It's a good chance, right in the middle of your pain, to remember the ABC in CBT. Let the pain and shame you feel, let it go without hurting the dear person that you are.