Str8 - Since you, yourself, say that this fellow was possibly the best friend whom you ever had among the Witnesses, I would recommend that you NOT change your number. I would recommend that you give him the benefit of the doubt and assume that he is acting in good faith. As you are without a doubt aware, true friendship is something rare in this world. True friendship is precious.
I recommend that you have a totally frank heart-to-heart talk with this guy. Try to do everything possible - while maintaining your own integrity, of course - to preserve your friendship with him. I may be naive, but I think that this might be an opportunity to enhance your friendship. Of course, you need not bring up issues related to your sexuality [after all, that is none of his business]. You can simply limit your discussion to doctrinal or other issues. I think the most imortant thing is to be honest. Although, I wouldn't know you "from Adam," I do have the utmost respect and admiration for you, based on my reading your posts. You seem to be a person of phenomenal courage and integrity. In that respect, you're almost "superhuman. I have every confidence that you will do well by him, and by yourself, if you and he meet for a frank discussion.