Just want to throw this out there hat this is my first post on reddit!

Been out of the game for over a year now, which is very unusual for me. I'm a younger guy, who has his eye on a girl I work with.

Two relationships ago I got screwed pretty hard and have had little to no self esteem since. A lot of things happened between me and the ex and about a month after started dating a girl.

I was not prepared mentally for this and it didn't last long. I worked with her and it ended up a disaster.

What are some suggestions to building my self esteem again? I feel like I don't know where to begin on trying to talk to this girl let alone even date her!