go cold turkey on(= завязать с: If you go on this diet, you'll have to go cold turkey on everything from coffee and sugar to beer and bagels.ART Vancouver)
start over from scratch("Starting over from scratch" means doing something again from the beginning. You can use this phrase if you did some work but now you have to do it over again because you lost it or because there was a problem with the first version. VLZ_58)