In watching the team match videos with Carpe Diem, I notice that generally blunders are blamed on playing too fast which is probably the case most of the time. But it is very frustrating when I blunder after spending a lot of time on a move. I would be interested in hearing other's thoughts on why this happens (and more importantly, how to stop it), but here are my thoughts...
1) I spend a lot of time analyzing a line or 2 or 3 that I've become fixated on and maybe spend all of my time analyzing responses to move 4 or 5 in that line, but never really back up and look at alternative "move 1's or 2's" for either me or my opponent and miss something. In one of my games, I thought I had a forced win and missed a fairly obvious king move that forked a couple of pieces even though I had worked out all of the variations of the other king moves. Fortunately I only lost the exchange so it wasn't fatal, but still very frustrating after all of the effort spent on analyzing.
2) I spend a lot of time and look at so much stuff, I lose track of what all I've looked at and what I haven't analyzed yet. The analysis board on chess.com doesn't keep all of the variations I've looked at. Any recommendations on bookeeping while analyzing lines?
3) Sometimes I just look at so much stuff my head starts spinning and I kind of lose track of what I was thinking. In one game, I thought I had it all worked out, then played move 2 of my variation instead of move 1... doh!
Generally, I feel like I'm very vulnerable to tunnel vision, even at slow speeds. Any advice on how to break out of that? Realistically, I may spend 30 minutes or more on very complex situations and probably 5-10 minutes on "routine" moves. I find that generally after that length of time, I just keep seeing the same things over and over. I can slow down even more, but I'm not sure really what I'd be doing in the extra time other than analyzing the same moves over and over. 
I think I need a more structured way to approach my analysis.
YOU ARE RIGHT!