I was a longstanding director of our homeowners’ association. Our new president has been discriminating against me because I am a woman. He has cut me out of my own projects to meet with the "men" and talks down to me when I say something or give my opinion. At our last meeting, I accused him of this discrimination (his response before has been "you're a woman and your point is"). He stood up and yelled at me and demanded an apology. I hastily quit at that moment, even though this board is what I love. Can I sue him for discriminating against me as a woman? I realize that I work for free but does that give him a free pass to violate my rights?
As a volunteer, you probably don’t have a legal right to relief. There are a few cases that have found a legal right when the volunteer position frequently leads to paid work (e.g. volunteer paramedics), but most anti-discrimination statutes deal only with employees and not volunteers.
But since you were the director of a homeowners’ association, you may have an even more powerful recourse. I assume that the directors are elected by the members. You can run against the president the next time he has to stand for election. With your record of service and his record of bad behavior, you could probably marshal a group of supporters and make it a good race. There seems to be a lot more sensitivity to this kind of boorish behavior these days and you might have the satisfaction of showing him that it is not appreciated in your community. Persist.