Messy Canvas Addiction

I'm an artist who always starts with a blank canvas, but lately I've been having trouble letting go of my initial ideas. Every time I start a piece and it doesn't turn out as expected, instead of moving on to a new one, I keep working on the same painting until it gets cluttered beyond recognition. I end up with these chaotic artworks that are more like my personal therapy than anything someone would want to hang in their home. Why do I have such an attachment to unfinished projects? Should I just toss them and start fresh each time?