Non for profit/Volunteer Harassment

[ugly4us]

I'm an Iraq Veteran who was working with a veterans non-for-profit organization as a volunteer. After some time the leaders of the local chapter and I began to butt heads. They grew increasing hostel towards me. At one point they sent their "mental health expert" after me because I was having "anger problems". This woman has no qualifications as a mental health expert though. After this attack I decided to leave the organization because it was increasingly frustrating for me and the leaders seem to be growing more hostel. I did in fact start seeing a qualified mental health specialist, through the VA, at this time because I was so shaken by what was happening. I have a mental disability, as an Iraq Veteran, and the leadership of this organization had me so unsure of my own actions. After attempting to leave I started getting even more emails and phone calls from the leadership. I finally had to write to the national office to try and get them to try and stop contacting me. In this contact I did threaten to hire a lawyer. It stopped for a little while, but I received another email from them recently and worried they might start bothering me again. I'm wondering if there is anything I can do legally to get them to leave me alone? Does volunteer harassment fall under Labor Law? If not is there some other category of law this might fall under? Since I have a mental disability, that they knew about, and started seeking therapy for it, might this be some kind of mental anguish case?