Starting over isn’t failing at a project. Sometimes the second version needed the first one to exist.

A first version is often a way of finding out what the thing is. You cannot plan your way to that knowledge, you have to build something wrong and look at it. When you scrap it and begin again, you are not back at zero, you are starting with information the first attempt bought you. Throwing away the draft is not throwing away the work.

If something has gone bad, rebuild it from scratch in one sitting rather than repairing it. Do not look at the old version while you work. Compare them afterwards, and keep whichever parts of the first one you actually missed.