There are always those quilts that will get cantankerous, or not look like what you want once finished, or have lots of technical problems. This isn't just the haven of the beginner. I can do a number of projects well, and then run into a "problem project", and I'm ready to either pull my hair out or quit. I've learned that the best thing to do is to get rid of the "problem project" which I can sometimes do by giving it as a charity quilt, or even giving it to the Salvation Army. I just can't look at it, period. Then I start a new project right away so my skills don't falter and I've got something positive in the works. Works for me.
By the way, I think it was the pre-cuts you used. I won't use them at all because they are usually cut so wonky, and they always give me problems. When I cut it myself, I'm meticulous about pre-washing, starching, cutting on the correct grain, etc. etc. and I have a Quilt Cut 2 that really helps with precision cutting as well as ease of cutting. I'd much rather cut than rip out FMQ stitches.
Good luck to you!