Peace?

How come there are days where it feels peace totally evades me? I mean there is nothing wrong in my life at all. Everything from the outside looks good, but even from inside I can see nothing wrong. So where did the peace go. One tiny little thing comes up, remembering that I have not done something I should and, WHAMO, no peace.
Today I feel like heel. I had a bad attitude for two minutes yesterday and now, even though all involved have forgiven me, I still feel like a heel. I know that in the final end of it all it is cause I am not forgiving myself. That is something I struggle with a lot. Things can be totally in the past for everyone, yet my mind goes over it and over it.
Well there you go. Nothing for a long time then, suddenly here I am back with a bang.
Have a good day. And don't forget the things you do probably bother you a lot more then those around