Welcome DP=) You've received some good suggestions, so I won't repeat. I just want you to know that you've found a good place here with people who care. I'm new and learning to navigate, but have found such comfort here that I wanted to pay it forward.
You are battling depression on many fronts. The good news is that you have "reasons" for your depression, which will make it much easier to treat professionally. PLEASE continue to seek talk therapy. Do you have a pastor? You don't have to be affiliated with a church. Just make some calls and ask for help. They will not turn you away.
It's good medicine for you to keep busy helping out your parents. You are not useless. You are not worthless. You are sad and heartbroken. Take it from the human "Humpty Dumpty"...you can get it back together again. We're here for you.
~~Dixie