Do you know someone that HATES for you to do good? Someone that doesn't want to see you happy if they're not happy? Or, someone that feels like you can't have or do shit if they can't? I'm pretty sure we all do. I know it sucks to have someone around you like that. It's nothing but negativity and it saps you of all your energy. People like are very envious and jealous. And we all know that envy and jealousy is a disease.
Those that suffer from this disease will do anything to bring you down and make you feel like shit. They will always point out your flaws and past mistakes in hopes that it will hinder you from something that they don't have: happiness. They simply live by the "Crabs in a barrel" philosophy. That, anytime you take a step up, they will snatch you back down (or, at least try).
If you know anybody like that, remove them from your life. They will bring you no good and only bring you down. Do not make excuses to keep this person in your life. Just cut them off entirely. It's whats best for you overall.