If you need to translate the word 'hypocrite' that would be лицемер. But it has a different meaning. It means 'pretend, wear a mask', often used in politics, etc.

In your case maybe these would fit: Я держу своё слово (i keep my word, promises), Я не бросаюсь словами (this one is probably close to what you are trying to say, meaning i don't just say something and forget about it).