But make sure that it IS therapeutic. I just started knitting and I get so aggravated when I make a mistake because I don't know how to fix them yet. Both today AND yesterday, I had to go to the knitting store and have my errors repaired.
I think when you're stressed, you should knit or crochet (the latter is soooooo much easier!) something mindless. When I crochet, my blood pressure drops signficantly. When I knit, I have to focus so much and sometimes even that isn't enough. I will say that if I didn't have a shop to go to and have the owner help me, I would have quit because the errors in knitting are just so different, and usually befuddle me. I've crocheted a lot and errors there are a CAKEWALK to fix. But something about knitting just appeals to me more.
As for knitting a dishcloth, do that, but only if it appeals to you. If I can't knit because I've screwed up my latest project and have to wait to go to the shop, I'll pull out something I'm crocheting. I don't find making a dishcloth very satisfying, but that's just me. (Unless I'm trying a new stitch.)
You do sound like a Type A. I'm that way sometimes, and I don't like it. But we are who we are. And, as another poster mentioned, $37 isn't bad for therapy.
Just don't quit. Take a nice long afternoon nap, pull out some pretty yarn this evening, and start a pretty scarf or shawl.
Who knows, maybe the yarn you threw away was retrieved by the knitting goddesses who have already put it back together and woven something beautiful out of it?
Hang in there. :hug: