What should I do about being sexually assaulted on a commercial job by my boss and then being fired for not having sex with him?

I was working for an illegal immigrant who was also my boss. Almost every day he made sexual comments and on two separate occasions sexually assaulted me. After the first time he apologized and promised it would never happen again and then a couple weeks later he locked me in a room and sexually assaulted me at a job for Altus construction in bb&t downtown Roanoke. I have made altus aware but don't know how to pursue legal action