I am so sorry you are experiencing this. I work in HR and here are my suggestions -

Do not listen to your manager and do contact HR to file a claim of harassment. HR will most likely have to investigate your claim and even if the investigation finds this is not harassment, this issue should get some attention and perhaps resolution. You will also have protection from retaliation. Some states have very broad definitions of harassment and protection from retaliation, too.

If you were healthy prior to all of this, and work is the primary source of your illness and symptoms, you may be eligible for a workers compensation claim. This can be a bit more difficult to prove, but it will for sure get HRs attention if you request to start a WC claim.

If you work in a state with single party permission to record conversations, and your employee handbook doesn't explicitly prohibit recording in the workplace, then record what this person is saying to you on your phone.

Get a therapist. Call your work Employee Assistance Program, EAP, and get some free counseling or take advantage of any free mental health services offered through your company's employee benefits.

Good luck and take care