He left me for his side chick 🐤

My bf left me for his side chick and I feel really bad about it. I can't help but feel like there is something wrong with me.... I just don't know. I can't understand why he would choose her over me. She is 37 with 4 kids, no car and I don't think she works. I don't have any kids, I have a really good job and my own car. I always made sure that he and myself were taken care of. I never looked down on him for any reason. He was my everything. I know I probably sound really stupid and I need to just move on, but now I'm afraid to. I keep feeling like I'm just not enough. I'm not pretty enough, I'm too heavy, and just plain unlovable. My heart hurts and I can't make it stop....