Been there; done that! I can totally relate. It seems once I notice that I've messed up, that's all I look at. What has helped me in the past is to write down every day in something called a GLAD log. Gratitude, Learning, Accomplishment, Delight. When I have those days, i look back and review that log to prove to myself that I'm not a failure and always mess up. This has really helped me put things into perspective. There are other varieties of logs out there. The gist is to write down all of your accomplishment no matter how big or small they are.