I am stressed all the time. I often say that "I'm not stressed, stress is me." Friends, family and teachers know this so well that they have actually become able to spot the signs when I'm particularly feeling it - I can't get sentences out straight, just words, touching my hair/pulling it a lot, going from outgoing to quiet in a few minutes... this may be particular to just me, but I'm sure others go through similar.
I get stressed out very easily, I'm not sure why, but I think it's because I'm constantly worried about school, exams and doing well in life. It's like a little pyramid of stress - at the top, I have school/exams, then underneath that I've got health and my body, then friendship and family, then the little things like remembering to hand things in on time or buying birthday presents. It's as if when I'm not worrying about one section of this "pyramid", my mind suddenly panics and remembers all the things I have to be stressed about...not a fun thing to live with.
In terms of dealing with it, I don't really deal with it. I'm not an upfront person. I tend to just ignore it and push it out of my mind and hope it goes away, which rarely happens. I've tried all this positive thinking and taking deep breaths and exercise and drinking water to battle stress stuff, which have all been misses. I'm at a complete loss at how to deal with it, honestly.