I'm tired

I need advice on what you'd do in this situation. My fiancé and I argue over everything. He is really particular on how he wants things and somtimes he can be very rude. But yesterday, he left all day to help his mom while I'm not feeling well and I'm with our one year old. I don't care if he goes but staying until 11 pm to fix her house and microwave and clean it is too much. But I let that go. I had to chug caffeine yesterday to keep my energy up. He did ask me before he left to do something about MY mail. But I had to watch our son and I cleaned the entire house to forget about how I was feeling. I organize my mail but I don't get rid of it and put it neatly on my side of the night stand. This morning he's being rude about things. But then he sees the mail and says, "I told you to do something about this mail. You did a million other things but you're not doing what I say." I honestly just wanted our home clean and I needed to watch our son. I was going to do it this afternoon. I just ignored him. And the mail isn't even like this ugly horrendous pile. It was like mayb 5 pieces of mail. Should I just ignore him and do it on my time? How do I handle this ?