I suppose this depends on what you feel you can do to appreciate this relationship as it stands. Do you think you can successfully introduce more clear and firm boundaries? My concern for you would be leaving this volunteer position altogether if this issue is not appropriately addressed. It sounds like a wonderful organization to be part of and i think it's one of the saddest aspects of having BPD - we very rarely meet the kind of people who impact upon us so electrically. But when the circumstances don't align we're left feeling horrendous, stripped of yet another chance to feel that wonderful and valued. I hope you can create a healthier more balanced relationship between this person and yourself - you're right in that avoidance rarely gives us the cognitive satisfaction we need and can often times lead to more negative situations that we reflect upon sadly.