It doesn't seem like you did anything wrong so try not to feel guilty. Parents should be supportive and maybe they are partly responsible for the problems you are having so don't let them make you feel bad.

When you said your dog was neglected I assume he has to live outdoors so you can't have him in your room? Is it possible to have the dog in your apartment? I have often shut myself in for years at a time and my dog stays in my bedroom with me. Your dog will probably be quite happy to be locked in with you when you want to be isolated and might cheer you up a bit.

I've been having some similar problems but I don't take medications. I really needed to get some things done today, but my sister who shares the house has been so nasty that I don't want to do anything that would benefit her. She woke me up shouting curses in the hallway and then kept yelling nasty things while I shut myself in my bedroom. Things are really ging downhill because of increasing debt and I'm less productive in a toxic environment. I'm not sure what to do either. So good luck with your situation. I hope you find a job to please yourself rather than what your parents want to do.