I’m 28 and I’m struggling with getting over someone.

I am a male 28 years old. I have been struggling with loneliness for a few years now. I have low self esteem and confidence. I started a new job and met a nice co worker. We met at job orientation hit it off pretty well, we exchanged contact info and played some games. I have tried to setup things to do outside of work and every time they would cancel last minute, this has happened 3 times. I understand this is never going to workout and need to move on. The moving on part is where I’m struggling with any advice?