The best way to stop the faa from looking is to be proactive and face it head on.

Talking to ALPA and then doing what they suggest is important.

Having an assessment does not automatically give you entry in to HIMS. All it does is lets a medical professional asses you and see if there is an issue. If not you are free to go about your life. If so, then you are doing the most proactive thing you can do and the FAA will note this.