It is hard to survive an event with mean in laws or mean family. I just don’t go to events anymore, I refuse and avoid. I let my husband go alone or we both dont go unless its mandatory. We literally stopped going to things after a few years of marriage, its the best way to keep happy. Understand your MIL is unwell, just go visit her, no need to visit an event. Phone her daily. Going to an event and feeling uncomfortable is a bad feeling and I know it well. I hope that you can just avoid events completely because there is no point going somewhere where you feel you dont belong.