I just don't know how my ex does it....I've tried going on dates and flirting with other guys since…

I just don't know how my ex does it....I've tried going on dates and flirting with other guys since we've broken up and it just doesn't feel right. He flirts with other women, and I deserve better but it's like nothing else feels right, and I just don't know what's wrong with me...I wanna move on because I need to but I just don't know why I can't 😪