Relationships ebb and flow... I think trully that some people are brought into our lives to teach, provide comfort and love for a certian time frame... The break ups are hard and giving your trust again is difficult (I still haven't found a way to do it).
Give this guy a go! take it slowly and surely and see what happens. If you are meant to have a romantic relationship then it will happen if you allow your heart to be in the right place at the right time.

I don't think that what experienced were Bi-polar symptoms...As I understand it, Bi-Polar usually encompasses a manic time, true highs without fear or knowledge of the consquenses - you were just trying to keep your self protected.