Depressed

I'm an 18 year old high school student. I'm on meds for my depression but they don't always work. Right now I'm going through an episode of severe depression and I've come to realize that I don't know what to do. It's one thing if I were having a panic attack, they can send me to the nurses office and have me lay down and consol me until it passes but with an episode of depression what can anyone do? I don't want to just sit through class feeling miserable and wanting to cry but I also don't want to cause a scene. What could they do for me anyhow? Sit and tell me to get over it or tell me everything's OK when it obviously isn't? What am I supposed to do? As a student do I make my situation known to the teacher or do I take matters into my own hands and go to the restroom and wait or cry it out? I need help with this, I'd be greatful for any advice.