What to do when you feel useless?

I just feel useless in life, I don’t know why. All my friends are living great lives; they all have boyfriends, I just want to stay single and live my life because I’m a very independent person. So its my own decision but I’ve just been depressed lately I just have myself and no one else to talk to. I don’t really want to talk to my friends about it, they really don’t help much. What should I do? Should I still live my life while I’m young and wait till I’m older for a relationship. I know its my choice, but what would you do? Please don’t be rude about it