I agree wholly, he's not responsible for his brothers sexuality. I would even guess that his brother does not remember the incident, or much about it either as he was so young.

You can't help him that much - you're not a therapist.. I think he needs some professional help. You can support him, let him know that you are there for him, but there is not much more you can do.

Therapy - I understand that there is little money to spare. But there are places that offer therapy in the States on a sliding scale. You can look online to find some, or contact social services or human services at your local city state/government to find out more. There is group therapy that costs less too. There are also places online that can offer therapy, though I should imagine they need a little bit more research before signing up to anything. I've seen some for about 100 bucks for four 30 min sessions, which at $25 per session isn't bad I don't think. Also, can he ask his parents for some help?

I do think that he needs to try and sort himself out, especially if he is to expect a healthy, equal relationship.

Best of luck to the both of you

Hugs.