All this sounds like me. I do it for my own pleasure. The quilt never turns out like the pattern I start with, much do to this "fact." I call them morph quilts. They always turn into something else.
I'm working on one now that I will post when finished. It is really turning out nice even though I've cut down the blocks to make them the same size even though I measured and cut carefully (I thought), had to fuse a wonky sash because there was no longer room to sew the blocks together and so on and so on!
Be proud that you made a quilt at all. That's how I look at it.