Are friendships even real?

I try to keep contact with people to keep "friendships" going but i always slink back to being in complete isolation. I like to talk to people once in a while, but i can't help but to feel like im "using" people and annoying them with my words. Those "friends" usually say stuff like "we miss you" or "where have you been?" and try to reach out but i just don't feel deserving of having friends and never really feel like part of a group, i know im not part of the inner circle of true friends, im kind of just sometimes there, i feel like they just pity me honestly.