I'm so sorry to hear. Is staying with your brother's family for a few weeks an option? Just to get out of the current negative environment and give you some other things to think about.
Right now you need someone to be there for you - in your current frame of mind you cannot possibly offer support to your mom and dad as well. And therapy will just have you running round in circles if you cannot implement anything you have learnt.
Is there an adult education/college in your area where you could further your education but be around a slightly older crowd?
My social circle has always been around older people - I would not have coped at a normal university, so I studied correspondence while working too.
Are there other social clubs you can join in order to meet new people? Or a BP support group?

Hang in there, and in the mean time I'm here to listen and support as much as I can (((HUGS)))