What am I supposed to do with mother-in-law hell?

When adults live in close quarters as you are doing, it makes for a lot of tension and hard feelings. The best thing you can do is to find ways to get out for a while. Walk the dog. Run to the store for milk. Take any opportunity to get away by yourself. Hopefully, that will ease the tension. Since you can't move right now, and arguing would get your nowhere, it's best to just make it work for another couple of months.