WAIT ONE MORE QUESION WHAT HAPPENS IF I CANCEL THE DAY OF? OMG~! WILL I GET IN TROUBLE? I CANT DEAL
What's the worst they can do? Lecture you, pressure you, apply guilt? I'll tell you a secret from my teen years -- I've never admitted to it before. When I was getting yelled at, given guilt and grief, I stared at the other person's nose and thought about how ugly they look when they are lecturing, and said things to myself like, "lecture all you want, you can't really tell what I'm thinking, you stupid jerk." I couldn't be overtly rebellious at the time, but I could think my own thoughts. Eventually they give up yelling and go do something else, especially if you just keep staring and don't answer.
I'm more concerned about your suicide thoughts and feeling like an alien. Please consider just going to the emergency room if those thoughts get too strong.