You're post is SCREAMING bpd, and unfortunately I relate to everything you wrote all to well. Whatever it is that you feel inclined to do... do the opposite. I'm speaking from LOTS of experience.

I do not see him as being avoidant, but rather establishing boundaries for himself and you. Because he realizes that you idealize him and the situation. The feelings that you have for him are real but they become unreal by idealizing. Whether he is in your life or not is not the deciding factor on whether or not you're a lone wolf. That would be your choice. I think, it will be helpful for you to try and decipher what the "real" emotion is vs that which is idealized and keep what is real in perspective.

My advice is don't write letters, don't get into explaining over exaggerated feelings/emotions/idealizing, don't get gifts, and there isn't a problem until he says there's a problem. In fact doing any of that will probably have the opposite results of what you want. A good way of ending it might be to go out for a casual dinner or ask him what he'd like to do. Whatever the case may be keep the conversation light and avoid any topic related to psychiatry. If he declines, accept it graciously and offer to keep in touch.

If you want to take a dbt approach prepare yourself now for how you will cope in a constructive way should he decline.

I hope something in all of this helps. I've been down the same road a million times, and I don't envy you. It's not fun!!

-cbox