I'm thinking of moving 1,500 miles away from my husband for 6 months
Why would you want to move so far away from your husband?
My husband has a job in a place I can't stand.
I understand that it can be difficult to live in a place that you don't like, but I don't think moving away from him is going to make the situation better. It might even make it more stressful for both of you.
But he has no idea how much I suffer from this. I feel like I can't breathe.
If it's that bad, then maybe you should talk to your husband about putting in a transfer. Just as you shouldn't put unnecessary stress on him, he should also try to mitigate unnecessary stress on you. Good relationships are about compromise, and the two of you will have to find a middle ground where you're both content.