I personally can't blame you for being sad about it. Even the thought of my ex with someone brings me down, seeing it in person would hurt a lot. It's nice to hear that even after seeing that, you made it to the top on your second attempt. You were able to put your feelings aside and focus on what you were doing, which shows strength.

About him finding someone else quickly, it could be that he only feels whole when he's with someone else. A lot of people, male and female, have those types of codependency issues. You not finding someone you're attracted to right away isn't something to be ashamed of or feel sad about. Would you rather rush into something and probably get hurt, or take your time and find the right person? Take your time, the person you're after is out there