What should I do

I’m not asking for someone to fix it. But here lately me and my SO has been arguing so much here lately. It’s over little petty stuff mostly. Idk he promised me the other night we could go see a movie tonight. But now he wants to wait until tomorrow. I have been getting mad over silly things lately and I have no idea why. Advice on how to fix this?😭 I don’t wanna lose him. And I don’t know how to fix the arguing.