Hi Mark - it is very sad that being inside feels better than being out - I guess that the routine and security were probably quite comforting. I think that at 20 now you have to say that the stupid days of youth are behind you and try to better your situation. You at least have an address, and that is a good start to go and get work. i still believe that good honest hard graft can help you. Firstly because it keeps you out the house and secondly because it gives you structure to your life and thirdly because it is your way out of the current situation. Have you been offered any help in trying to find a job?
The positives you have in your life are that you have a roof over your head, brothers that you get on well with, your health and your future ahead of you. My other half used to work with a guy who had had a bit of a mispent youth, he had a police charge sheet as long as your arm. When my husband first met him, he was working as a nursing assistant in a mental health ward and loving it, he was also in the marine reserves. he also got really into mountaineering. He has now put nursing on the back burner is married with a little boy and is currently serving with the full time Marines in military intelligence in afganistan - he was hand selected because of his mountainerring experience. What I am saying is that you have the power to change your own life, your background will be an issue for some people but not all. Don't make it an issue for yourself. Keep out of your parents way as much as possible and try to keep to the house rules. Maybe a few years down the line, you could get a place with one of your brothers.
Anyway, all the best and keep your chin up.