Is there a rape crisis line you can call? It woud be completely confidential and they may be able to arrange counselling for you. If the guy who raped you is a work colleague, then you will continue to face this trauma everyday, while he keeps harrassing you. You need to report him to your boss, the chances are he has done stuff like this before and without wishing to alarm you he could do it again to someone else.

This is a link to the resources listed on the PC resources pages.

Psych Central: Abuse: Sexual Assault

Please seek help.