Sundays are the worst

Overall I’m doing fine. I have a nicer apartment now, closer to work. I’m doing many activities and getting my shit together. Understanding why we were so unhappy at the end, but during Sundays I suffer so much missing him. I start self-doubting, start thinking how could I have expressed myself better, why would he let me go like this. Why would he never smile at the end even though he was saying he loved me, why it became that way. I might stay all day without eating because it reminds me of him and do nothing that I like instead but just scroll on insta. Idk why im being like this. I miss him so much and I did so many mistakes but it’s stupid to text him and I know he doesn’t want to text me back.