Just breathe, talk it out with someone you trust, listen to your favorite music. It's even good to sleep. I tend to try to forget i struggle with these things.
Depression Can be fixed or at least helped by getting medication. There is nothing wrong with asking for help from your parents and doctor. Dealing with Stress I like to write In a journal which helps me consider what is causing my Stress so I can fix it or eliminate it from my life. You can try spending 5 minutes alone in your bedroom with all the light off with you putting your feet above your head while you are laying down. (I use a wall to put my feet up) Close your eyes and just listen to your breathing, It always helps me with My anxiety.