I'm not good enough

ab
When I was with my daughters father he never acknowledged or even cared about how hard I worked for her. I got into a university with a high GPA, studying as a pre-dental student and would even work on some days (I had to stop because I was extremely overwhelmed doing this all by myself) I never got a "good job" or "I'm so proud of you" instead all he would do was fight with me because "I'm a horrible mom that's always away from her daughter" I was "stupid for wanting to go to school for 8 years" now that he's moved on all he ever does is brag about how he's so proud of how hard working his girlfriend is, she works in retail and has no college degree/isn't getting one at the moment... I guess I'm just kind of angry that he values her more than he ever valued me :/ why was I never good enough? I can't seem to understand it..