>>2 is right. It's really not your problem. Your mother is probably acting that way so that your father will stay. She most likely thinks that she won't be able to find another man because of her age, so she is kinda desperate for your father to stay with her. Women can act that way, it's normal, sadly, and I'm no exception either, women can try really hard in various ways so that a guy will like them, your mom just tries harder than most.
You can't really do anything about it unless you talk to her but I don't really think that that's a good idea. Just leave them be. Try to do some of the house work and you and your brother can work together for the time being. It's not your fault and you can't really blame them, adults can act that way sometimes. All you can do is love your parents, I know it sounds hard but at least try to think positively and focus on your own life rather than their's. Focus on things that are important to you like school for example. I hope that helped :3 good luck~!