Alas, with 14 comments already posted it seemed to me that the party was over, but I still felt the urge to contribute something. So I'm copying my remarks here, because as I thought about it on the drive home from work, I want to be able to remind myself occasionally of the immediacy of my message. Here's a practical answer that may be so close to home that we don't give it enough consideration in our search for philosophical solutions.
Beck, my compliments to you--I don't think I've ever seen the Moho angst more articulately or honestly described than by you and your questions. I'm going to share this with my wife, if you don't mind, because it verbalizes so many of the raw doubts and feelings we share. It will be a good place for us to begin conversation. Have you shared this and the comments with your wife?
This leads me to the main point I want to make: Spend as much of your emotional and spiritual dollars as you possibly can on your wife. Replace the soul-searching, doubting, rehashing, guilty, self-condemning expenditures of energy with investments of love, openness, gratitude and time with your chosen companion.
I say this at the risk of being mis-interpreted as a trite Mormon fix-all to a very complex reality. But I've struggled with your same list of questions. And I'll tell you, the doubt can go even further--now add on top of that angst, later on via life's disappointments, a generous dose of frustration with, and lack of respect for that chosen "eternal" companion. That's where I was, in an even worse place to be stuck, because it sounds to me like you still admire and appreciate your wife.
So how have I gotten past all this angst and downward negativity? I went back to the base of all human need, the wellspring of love and gratitude. Despite her faults, my wife has been my loyal companion, my standard bearer, my friend, the devoted mother of my children, the unintentional victim of my never being quite satisfied with her. I've decided it's pay-back time, and I'm investing again in her. After 26 years of marriage, our needs remain fairly simple: she wants to be spoken to more often, played with, cherished, acknowledged, affirmed. . . and so do I.
I still have my issues, but I can remember her more often. Once I started this pattern of giving back, I find the SSA is getting easier to manage, I feel more secure, and I have on less critical filters of my own making, the design of my own self-centeredness.
Note to self: in your never-ending SSA saga of self-discovery and analysis, remember the one who remembers you daily in her prayers. I love you, Sweetie.