Self-esteem issues? looking for a solution?

Its the old cliche once bitten, twice shy. You got burned in the past and now don't want a repeat. The thing I would suggest is getting yourself into social situations where you are all there for the same thing. I personally found martial arts helped with my shyness, it helped meet new people, set achieveable goals and helped with confidence. You could try a new team sport, learn a langauge or find a local club for a hobby you enjoy. Depending on your skills you can also do the reverse and try teaching a cl (yoga, a language, dance etc), again its all about meeting new people and feeling more confident about yourself.