Is it normal to feel strongly apathetic without depression?

I just don't know anymore.

I try to be cheerful, and I'm pretty good at actually feeling pretty content when there's other people around, so I can act for them. But I have a pretty hard time convincing myself that I'm happy. I don't feel close enough to most people to talk about it privately, and although I'm so close with my family and I love them, I can't talk to them. They know the me that I let them see, so they think they know ME and I don't know how to tell them just how often I think about what it's like when you die. I'm not trying to get attention.
I'm just tired. Anyone I know can argue that I'm a lazy person, and I'll be the first to admit my best friend is procrastination, but I don't feel like anything I do will actually amount to anything. It's feels like the motions of actually living is pointless. No matter what I do, if I get an education, if I get a job or a family, we're all going to die eventually. So what's the point? There's isn't. I'm an atheist, I'm pansexual and for the love of all that's imaginary, I feel like my body isn't mine. To top off the whole genderqueer-ness, I don't like my body image ANYWAYS.
And I don't know what to do anymore.
I don't want to live without a purpose, and I can't really be bothered to look for one, because as far as I can see, there isn't. You can tell me that I should be happy with what I DO have, but honestly, I feel like the hiding of everything from everyone has worn me down significantly. I don't want to tell people half the time because I feel like I'm annoying, and that they don't want me around. I usually try to stay off the topic of myself because I feel legitimately guilty, as if I'm monopolizing the entire conversation. I do my best to listen, and I think I do an ok job, but I... fuck I don't KNOW.
My confusion and need for reassurance from someone is bordering on the edge of hysteria, because I don't know what to do, but I don't want to ask. I'm just so tired. Of everything, all I want is to be numb. When I'm not around other people I'm filled with this lost feeling, like I want something to do but there's nothing that can hold my attention very long. I'm disinterested in the things I normally am so amused with, but I don't want to sit in the living room with everyone else. I actually really hate sitting with my Mother and step-dad, it makes me nervous and my legs and arms get really cold. I'll curl up in the chair, and hope no one requires me to say or do anything. When they do, I'll think of some snarky quip, a thoughtful comment or I'll just make a sound like a dying moose, to make them laugh or shake their heads. It makes me a little happy when my mother laughs, considering she always looks so unhappy. But then it fades and I'm left feeling empty again.

If someone could say anything of any kind of encouragement, or offer some help that might actually do some good, feel free to comment.