Hello and welcome to Psych Central! I can imagine what a tough work environment that would be. Having to try to be civil to someone who wrongly accused your husband and caused him to have to leave his job--and then to be treated differently by GM. You are amazing for being able to hang in there. Talk about stress!
I have not been in that situation, but I'm wondering if it might help just to see this job as a way of making money right now. Do what you need to do, and try (I know--easier said than done) to not think about the co-worker and how GM reacts. You can't do anything, alas, to change their thinking, anyway.
Celebrate each check in at least a small way. Imagine what good things you are accomplishing or will accomplish with that money.
Let's hope at some point soon your husband will find a good job. Ideally one in another city, so you can move on.
Of course, you can also keep your eye out for another job. At least thinking there might be another way out could be reassuring.
I hope something I have said might be helpful.
Again, welcome to Psych Central!