Since OT is not here to remind you (or is she, lol) I will do my best. You have always been SO good at setting personal boundaries and then enforcing them. What I see here is not so much giving up as that you are no longer willing to "play house" with this man who is unwilling, unable, or otherwise incapable of committing to you and a monogamous relationship with you.
Is it really his actions or your lack of patience that is getting the best of you? Maybe both I suspect.
I wouldn't beat yourself up too much over this. You are tired and you have learned to listen to yourself and how you feel.
Quote: I think this goes beyond the meaning of detachment. While I grasped that concept, I don't think I ever really got the hang of it. And it's going to be my downfall, I think. I know - I know, I've read & heard the definition of detachment. I think I've detached too far.
I don't know if you've detached too far. I think you have come to a point where you are at a crossroads. Remember, we LBS tell each other ALL THE TIME that when one partner wants to end things, or THINKS they do, that all hope is not lost. Just because it's now YOU that may be the one wanting it to be over does not necessarily mean it will be. The point is that you WILL do what you want, I've seen that over these several months, and I have no doubt that whatever you do, it will illicit some response from SO. At some point, beyond DB, beyond any plan to save a marriage, or a relationship I think one partner either pulls WAY ahead or falls WAY behind and it's at that point that people feel overwhelmed by what it may take to repair things.
Give yourself time. You may change your mind or you may not. I think you just need to take a break, as I think you have been doing, and see where things go. If nothing else, you DO have a strong sense of who you are now and that is invaluable.