I am truly humbled by the love and support that has been evinced in every single response in this thread. I am simply amazed.
Spritle: I had not seen your 1000th-post thread, since you began it during a time when I had no consistent access to the board. I’ve now read it, and am grateful for the tribute you paid me in beginning it and in the topic you covered – or at least tried to cover, despite ladies of ill repute bearing soft cheeses and misquotations from J. Alfred Prufrock. 
John Corrado: I got a chuckle out of you playing off the paraphrased quote in my OP, at a time when I needed a chuckle. I appreciate you and what you have to say, and still maintain that you’re the board’s leading expert on Pharaonic incest!
Francesca: You were the first to raise the recurring theme that much of what I’ve done has been to touch the people who are not passionate about issues and as a result do not post. But it occurs to me that maybe more people ought to be passionate about issues that will sooner or later affect them or their loved ones – but to keep in mind, as will be easier in such circumstances, that your opponent is neither bigoted nor a total idiot just for holding a different view than you.
Beeblebrox: I don’t think I’m Sisyphus, but the idea did furnish a useful metaphor for how I was feeling. Although for him and for me, if one let’s go, “it’s still rock and roll.” 
Triskadecamus: Brother, your loving support and prayers are always needed and always appreciated. But this time, your concrete advice was most important. I’ve read it, changed my thinking on what’s a possibility, and I will be acting on it. (Do you feel like Victor Frankenstein yet? ;))
Homebrew: Perhaps the single thing in the entire thread that touched me most deeply (as I have a hunch you knew it would) was your giving me back the Last Beatitude that I gave to JayJay when he needed it.
Guinastasia: I saw your thread, and now understand more of why you posted it. I felt my first answer over there was inadequate, and I’ve tried to say a bit more of how I feel (and answer Happyheathen’s tongue-in-cheek (I hope) comment as well).
Tris., Lissla Lissar and CJHoworth: Your prayers are of course something that I very much appreciate – but I must report to you as well that they were answered, promptly (alas, not the one for a job, yet) – in that the strength and encouragement that you asked God to give me, He gave, in large measure through the posts on this thread.
Grienspace: I completely understand what you are saying. Though I too do not doubt that we disagree on a wide variety of issues, let’s note that it is “issues” that we disagree on, not on the basic relationship that makes God our loving Father and Christ our Lord, Savior and Brother, and hence makes us brothers in spirit. And what has been said to me, I need to say to you: if people, especially Christians, who disagree read and wrote with as much respect and understanding of their opponents as you do, the world would be a much more pleasant place in which to live.
CJHoworth: Quoting the post-communion prayer on p. 365 at me was a stroke of genius; that is often what sustains me from one week to the next in keeping on doing this stuff. Regarding your not entering into GD that much, my POV is that all it takes is saying what we believe, regardless of what others may think or say or do. Although to that must be added caring about what they feel and say and do, because only by doing that, by showing love for them in that concrete and practical way, are we equipping ourselves to respond fairly and treat them with dignity and grace. And through this we are showing Christ to them.
London Calling: Your diagnosis was very close to being a bullseye. When one feels impotent – not with the sexual meaning but in terms of being unable to influence or affect the world around you (or seeing yourself in that state) one’s self-esteem is eroded away.
Hamish: You certainly did not contribute to the problem. All one needs to do is to see the other guy’s perspective. Not necessarily agree that he’s right, but simply to understand where he’s coming from. Then you can reason with him and show him where, in your opinion, he’s wrong, with some hope that you can communicate – because you’re aware of his point of view, and showing him yours on the basis of his.