Could feeling that way when you are trying to help be caused by feeling like you need to know what to do before you are told? This is how I feel. You know like I should know what to do and if I don't I try to fake it instead of asking. I wonder if you went to him and asked him what he needed you to do he could help you with these feelings of inadequacy and you would be doing things he really wanted you to do. It could be as simple as just sitting there holding his hand for a little while. Or you could take your homework with you and work on it there. That way he knows you want to be there for him and you have an excuse for not doing a lot.
Carrie