Never be afraid to lose someone. It takes away from your ability to provide to the relationship the love and support required to sustain it. When worrying about losing a person, it tells them you're insecure, weak and lacking in self confidence and that you'll fold when put under pressure and will ultimately turn them away. When all of your focus and energy is placed on another person, you lose track of yourself and your life's mission. You get what you focus on in life and if your focus is on "losing", you WILL lose. It's that simple. Instead, focus on becoming the best version of yourself possible. Set goals and then ATTAIN THEM. Do things that make YOU happy. Become the type of person that you want to be around. Do this, and then that person you feared losing, just might fear losing you.