Mia,
I think you have to weigh what works for your family overall.
If keeping him at this school is the least-worst option for your family because of where it's located, how much it costs, social opportunities, etc., and you can supplement the academics with afterschooling, then I say hooray for you!
I don't think you have to do anything you don't think is in your family's best interests. Period.
Also remember that if you make a choice and later find that the decision doesn't work for you, you can always try something else. No choice is set in stone! This is not a philosophical debate; it's reality. It's life. You can change course whenever you feel like you need to. And that's okay!
BTW, I wouldn't give up on getting some accomodations just yet. I know the conversation you had before wasn't the sort to make you optimistic, but stay strong! Don't resign yourself to the worst case scenario just yet, okay? <hopeful, reassuring smile and pat on the shoulder>
K-