If I'm making a lot of mistakes one day, I take a good look at whether those are project threatening, by project threatening I mean I'm either consistently gaining or losing stitches. I've had days where I just forced myself to plow ahead and get somewhere for the day, regardless of mistakes. The more you frog and are frustrated with things that aren't quite right, the more you'll find things that aren't quite right. Decide your acceptable error margin, set it significantly below perfect and just finish something. If you're not sure about it, don't weave in ends or block. Then leave it overnight and see how it looks in the morning.
There's something extremely liberating about knitting through a project and leaving the small mistakes. Perfection is for God. It's the little (and occasionally big) things that aren't quite right that make us human, so why shouldn't our knitting reflect that?
That being said, I made a conscious decision when I started knitting to only frog if I was going to lose the project if I didn't. I do usually look for the mistake, but for the most part, I just keep knitting. If, the day after I finish a section, I don't like how it looks or something is glaringly wrong, then I'll usually do the section over, but once I'm knitting, that time is only for forward progress. Trips to the frog pond only happen at the beginning of the session. Anything else is short visits by Tink-erbell to fix something small that I caught in a few stitches.
You should try it. Even if you have to start a project over at the beginning of the next day, you'll feel a bit more like you made some progress when you set your knitting down at night.