I'm sorry it's a hard day for you. I do understand the thoughts and feelings you are experiencing right now, I really do. I had many of them myself.
Just remember, introspection is GOOD; navel-gazing . . . ehhh, not so much. Try to balance this period in your life with 1 part introspection, 2 parts action, until you become more action-oriented and less melancholy.
It's funny, after all these years here I can begin to spot the profile of the successful DB'er. Those that have zero ability at ANY kind of introspection, learning how to realisticallya assess their relationship shortcomings and working on a plan to overcome them, inevitably fail.
But so too do the navel-gazers -- those that are still here, months and even YEARS later, thread after thread, post after post . . . so many words. At some point, you have to take what you learn in your moments of quiet introspection and turn them into ACTION PLANS, and begin the hard slog of executing those plans, step after step after step.