A hostile work environment due to that type of remark does fall under the guidelines for sexual harassment. See paragraph 2:

Sexual Harassment

Aside from that, OP don't let a (probably jealous?) coworker cause you to cry.

You don't mention if you have talked with the boss or HR about this. But if you haven't said anything to them it's a bit early to think about lawyers kwim.

Go to HR and your boss with documentation, keep track of every date/time you were told this by other employees and who said it and what they said. Like walking down the hall - that's the sort of thing you need to document...'walking to the north elevator at 5pm on Oct 1, Joe Smith pointed at me and said to Mary Jones, there's the one sleeping with John Boss'

Put it all in writing, just the facts, and state in your letter that these unwanted sexual remarks are creating a hostile work environment and interfering with your job. Good luck and don't let a jerk coworker get to you