train wreck
1. A major or total failure, disaster, or catastrophe. This project has become an absolute train wreck. We've wasted so much time and money already, I don't know how we'll make up the losses. Despite a stellar cast, the film turned out to be a real train wreck.
2. A person whose life is a complete mess or is in total disarray. I don't know about my relationship with Kevin. He's a bit of a train wreck, between you and me.