One man treated you thoughtlessly, if he actually knew you had feeling for him.  Writing off all men bitterly because they don't read your mind is self defeating.  Dating sometimes is practice for the next relationship.  Men who don't declare their feelings or intentions directly at some point are not marriage material.  I think you ran with a ball that was never thrown, unfortunately.  

Also...looking for love in the workplace has its risks.  Try dating outside of work (volunteer, clubs, church, whatever) so you can avoid messiness when things don't work out.