If its not documented it did not happen.
Make sure to get screen grabs of everything, and do not talk about this with anyone at work.
HR is not to cover/protect you, they are there to cover/protect the business, and want you to tell them of a problem so they can cover the business from law suits, their job is to protect the business. Honestly they don't care about you at all, or your family...that just the way it is now. If you say anything then you are marked as a trouble maker. The HR people are afraid to do the right thing as they have families as well and need their jobs. If a HR employee stands up for what is right or in the best interest of the employee they will not be working there long. Do not trust them they act like your friend but they are not.
Start actively looking for another position. But do it quietly do not tell anyone at work.
I went through something like this, and it was a complete nightmare. I worked in long term care ( 240 beds), in a management role. I sat on the employee relations committee which I was told I had to after I started working there. This committee fell under the HR umbrella...which I knew would be a problem. Keep your mouth shut and head down was my motto in these meeting. There were rumors that the therapy manager ( a married women in her 30's w/ kids) and the student trainee( a college guy 20) had something going on. Now they were rumors and was not any of my business, I had a job to do. I was working late one night and went to the therapy room to file some notes in the charts, and walked in and they were in the office which has a large window looking out onto the therapy gym....there they were basically making out. I turned around and walk out went to my office and left for the day. So the next day I have a care plan meeting with her, and after the meeting she asks to talk to me. Then she says I saw you last night and I said where, she was like in the therapy room, I said oh I did not see you, I saw the lights off and thought you were gone for the day. Then she said I know you saw and you better keep your mouth shut or I will get you fired. I was stunned... From that moment on I knew that I had a target on my back. A few weeks later they rearrange the disciplines and guess who my department all of sudden fell under... therapy. I documented everything thing she sent my way, copies of emails, notes she would leave on my desk that she wanted me, and basically threatening me constantly, I did not talk about it with anyone. They took me from salary to hourly, then I got in trouble for overtime, then wanted to make me salary again which I declined then told me I could not have any overtime, but I better still get my job done, even if I had to work off the clock. Yep had it all in emails.... Finally one day the HR dept. from the hospital came in apparently they had fired a therapy aid and she got a lawyer and filed a complaint. They said that they knew I had seen something, and I needed to be honest and tell them the truth....basically were badgering me.....I was like I not telling you anything, and your making it worse for me just by talking to me. So there was this big investigating going on. During this time I found another job. I went in to resign, and the HR people from the hospital were back and waiting for me. I told them I had nothing to say, and they kept on asking questions. I just said I am not saying anything why are you harassing me?... I got up and walked out of the room, and went to the Administrators office handed him my resignation which was immediate. While reading it he turn red then pale, and I said have a nice day. Before I could get home my phone was ringing off the hook, messages from HR, the director of HR, and some Hospital administrator, all wanting to talk "calmly" to me about what was going on. They kept on calling for days. Finally I pickup the phone and said if you don't quit harassing me I am going to get a lawyer, and I have all the proof I need to show that I was harassed on the job, and the Administrator knew and took part and did nothing, and was harassed by my direct supervisor over her indiscretions. Leave me alone and hung up the phone. Funny thing is I got a letter from a lawyer a few months later and they gave me 6 months severance package and cleared my bill at the hospital.
Lesson learned, when something like this starts, get ahead of it, start looking for another job. Its not worth it, life is to short for this kind of non-sense.
Good Luck and Pixie Dust to you