Let’s see: You are willing to physically assault your coworkers and go to jail but you’re not willing to report to HR? I do understand how strongly you feel about the situation, but you aren’t making any sense. The price you would pay for getting even by hurting these people is much too high.
You and your fiancee are in a hostile work environment. There are laws and company policies intended to protect workers like yourself. Human Resource departments are generally bound by rules of confidentiality.
Do yourself and your fiancee a big, big favor and resist the impulse to get physical and take the problem through proper channels. If you don’t get a satisfactory response, consider getting a different job. Adjusting to a different job is preferable to adjusting to prison!
I wish you well.