I feel jealous when my friend hangs out with other people

I constantly feel jealous when my friend hangs out with other people or adds people to our call.I usually leave the calls with some excuse but I still feel upset when they hang out or text people while talking to me.I feel selfish everytime.Just because I dont have enough friends to talk to I seem to make it everyone else's problem.i dont know,is there anyway I can make myself feel better about this?