Baby steps, people. Inspired by this Quora thread.
Give at least one genuine compliment every day.
Making other people happy will make you happy. Try it! Emergency Compliment can give you some ~creative~ ideas.
Valentine via ChoBeArtandDesign on Etsy, $3.75.
Etsy / Via etsy.com
Thank your partner for the small, expected things.
Research has shown that gratitude is maybe the most important factor in predicting happy and successful relationships (more on that in "17 Small Things You Can Do To Have a Stronger Relationship Today"). Expressing that you're grateful even for the small stuff will really make your partner feel special — and it'll also make you realize how lucky you are. Everyone wins.
Focus on adding more healthy foods to your diet, rather than eliminating the "bad."
Download the app Wholesome, which can help you track your vitamin and nutrient intake each day, and can give you recommendations of foods to eat that will help you reach your daily goal of all the good stuff you need.
Diets often fail in the long-term, and in the short-term they can make you feel miserable and cranky and deprived. Instead of focusing on all the foods you can't or shouldn't eat, try to think of food as a way to nourish and sustain and fuel you (assuming you don't have a health condition, like diabetes or high blood pressure, that requires you to limit certain food types). It's a happier way to live.
Learn to say "sorry" to loved ones and friends in a meaningful way.
Take responsibility for what you did (none of this "I'm sorry you feel that way" passive garbage). Show remorse. Promise to do better next time. And actually mean it!