It doesn't sound to me like you've failed at anything.
I've always found it quite easy to get into a postion with people at meetings, where I grate against them or them against me. And the anger is never big enough to cause a huge fight, but it sort of goes on irking me for awhile.
My head though (on the other hand) tells me I should've done all this other stuff and goes on and on about it, for days sometimes depending on what else is happening in my life.
Try not to give yourself such a hard time. You're not a mind reader.