Can't Focus, How About You?

I have been having difficulty staying focused on a project long enough to finish it. This has been going on for some time. At first I thought it was my Parkinson's because it made it difficult to keep my hands still. But then a new procedure (okay, brain surgery) fixed the constant, unplanned movements. But I'm still working on, say, 10 or 12 different projects.

I start a new project with the greatest of enthusiasm. I cast on, knit a few rows, and then find I've made a mistake...dropped a stitch, knitted an incorrect stitch, etc. The first few times it happens, I sigh, frog it and start again. But by the time four or five ripouts happens, I give up, toss the offending project in the "Corner of Shame," and start something else.

Or, I don't make any (or many) mistakes, but the project just isn't coming out as I hoped. Maybe the yarn I chose is scratchy or doesn't drape well, or I don't like the color as well as I thought when I bought it, etc. Then there's always the dreaded moment of realization that, because I don't do swatches (I know, my bad), the project is coming out too small. Or way too big. So, into the Corner it goes.

Do you have similar difficulties? If so, what do you do to get yourself back on track? Any secrets you care to share? I'm grateful for any tips you would like to pass along. I thank you and my unfinished projects thank you!