This seems pointless

I don't feel like telling my whole story, but currently I have almost no friends, and I feel rejected by my family. I only have two friends irl, and then one internet friend, but they don't talk to me much and aren't very supportive or helpful. I've only really got my girlfriend, and she's the only thing I live for. But I can't even openly be with her because if our parents find out then we probably won't be allowed to be together. Also, I'm doing worse and worse in school and I'm always exhausted. I have trouble falling asleep and sometimes get nightmares. My life feels pointless and worthless, and I'm just tired of it