While I've never done this because of a breakup, I can totally understand how it feels to have your heart shattered to the point that you want to change into another person to alleviate the agony. You become irritable, cynical, and a jaded ghost of a person. However, the most precious asset after a breakup is yourself. You need to believe in yourself again even though your ex didn't give you a chance to do so. The best thing you can do for yourself after a breakup is to give yourself time to heal. Go through the motions of your life but don't do anything that will hurt yourself or others. Take care of your body by eating well and getting enough sleep. Make an effort to stay connected with friends and family members. These things will help you get over the loss more quickly. If you've been separated from your ex for a long period of time and you both agree that breaking up is what's best, then do it. Don't try to force the issue if they just aren't right for each other. Although, in some cases, waiting until you're ready may be too late.