Just got married

I just got married and I’m already having problems with him. I constantly think he’s thinking of hi ex girlfriend because we live in the same area where they used to be together!! I really dk love him and so far no one knows about our marriage I haven’t told anyone from my family because he wanted us to keep it private. I’m so scared I don’t want to think that I made a mistake on marrying him. Has anyone had problems after your marriage?