Stop comparing yourself to a possibly better rival
All the principles of success in life are identical. Whenever you intend to improve yourself in some area and grow, you must basically stop caring how somebody else is doing. Because you are primarily not interested in whether somebody else is improving or growing. It is all about you. Focus on yourself. Jealousy is a daughter of poor self-image. Whenever you are inclined to compare yourself with others and seek in them something at which they are better, you will find it every time. But in so doing, you tend to forget that if you try to find something at which you are better than others, you will also find it. Because every person is a unique individual with distinctive strong points. Each one of us has something another has not.
That is why you should calm down. There will always be prettier, richer, more experienced… (add any adjective) people than you. And do you know why? Because people will always differ from each other. Ask your partner what he likes in particular about you. It is simple. If somebody sincerely loves you, the reason is: the way you are. To him, you have no competition. Not because you are perfect, but because you have specific qualities that are important to him at a given time and nobody else has them – cannot have them, because nobody is like you. If you are unable to accept your strong as well as your weak points as an inseparable whole, and do not like yourself for what you are, you will never give others the chance to love you sincerely. You must not be ashamed of being an original. Otherwise your partner would have to love a false imitation, someone you pretend to be and who is factually worthless. Whenever you feel inadequate, you decrease your own innate value. Only because you don’t see it. This does not mean you do not have it.