I'm a perfectionist by nature so when I find myself in similar situations as yours, I know I won't be happy but I can still chalk the crappy outcomes as 'learning experiences'. That mentality helps to lessen my inner tension. I currently have a large lap quilt nearly finished under the machine. I've had nothing but problems with thread, lumpy block joints and you name it. I've cursed a blue streak, walked away several times and have labeled this project a 'utility quilt'. It will get worn out in the washer and I won't care. I'm stubborn enough to finish it because ripping it out or giving up is unthinkable. :) Be kind to yourself. Most things in life aren't perfect... including sewers. :)