Talking to people is so hard

I already stated that I'm not the most sociable type, but I don't understand why it's so hard for me to interact with people. The thing is, talking to people itself is not hard, but it's so exhausting. Whenever anyone wants to call or text me, I just want to dig up a hole and bury myself in it. In public, I can interact with anyone just fine! When I'm at home, though, that's the problem. I just want to stay away from the world, and sometimes I forget to talk to people for days on end! Maybe people can relate, and maybe it's normal, but I still can't help but feel weird for being this way. 

:(