I don't blame you. Rebuilds here take so long, and then you run into a dynasty like the Bigshots who have both great players and seemingly, a huge cash stockpile, and you have to rebuild again. Rather than quitting, you could do a rebuild with a minimal amount of attention - logging in once a week or once every 2 weeks, and you'd be training up your next core.
If you do decide to quit though, don't forget you made a big impression here. Your teams were always tough to play against, and you were always very active on the boards. Definitely made my experience more enjoyable. Good luck where ever your attention gets refocused.