Well, my son is close to your age (25 actually) and he is living me and his sister. I have the feeling that you mite be struggling with depression; my son and I think that he mite be struggling with that too, but he hasn't gotten checked for it yet.
I can't diagnose you, but I would try to get it checked out. I am thinking about trying to encourage my son to seek help. There is a clinic down the street from us that has a mental health program that works with people as far a money goes--and they also help people get public assistance if they want it and need it. Perhaps you can see if there is a place like that in your area? I would definatly at least try to check it out.
Depression can be a b***h, and other people don't understand what it's like, and we tend to be very hard on ourselves.