Tired of feeling like I need to drop everything just to make my child happy

I’m sorry if the title sounds harsh but my son is 8 and being stuck at home with me for the past 4 months has turned him into a different child. He’s so impatient and has such a temper now. I also have a 1 year old to look after so I am quite busy. He always seems to ask me to do something at a time where I am busy doing something else. When I tell him to wait a bit he gets mad and stomps his feet and whines and constantly nags me every 5 mins until I give in, and when I scold him he pouts and tries to make me feel bad. Lately my 8 year old is way more work than my one year old. He is so incredibly demanding that I’m feeling extremely worn out during the day. I love him to pieces and he’s an awesome kid but seriously please give mama a break once in a while. Anyone else going through this with their older children?