in all honesty, ive been wondering the same thing myself recently. youre not alone man, i promise you that, im 18 as well and ive been having alot of stress being thrown at me too, and to answer the question about the breathing thing, yes, breathing and meditation can be very relaxing to the body, no it does not solve everything and can calm you down in that short amount of time like a "fix" such as alcohol or smoking can another thing you might want to consider is a therapist if it gets too bad mine helped tremendously, and now, i even have a medication to help with my panic attacks, before him i didn't even know what a panic attack was! haha but instead of smoking, try alternative sources for relaxing, things that wouldn't be detrimental to your health and such things like playing a good video game, playing an instrument, taking up a skill like cooking or digital arts, there is alot of options and really, all you have to do is look for 'em ^_^ but something i HIGHLY recommend is to look into meditation now there is alot of people saying "oh this and this is meditating" "finding your inner self" and all this other spiritual bull, that makes no sense at all and is nothing more than a waste of time meditation is nothing more than a breathing skill and mindfulness try your local bookstore and go to the psychology section to find something on this, but try to avoid anything from the new age section as it will prolly give you the wrong idea, then you start wondering where ur going wrong and just get even more stressed haha. that would be bad