For the last two weeks or so, it has been difficult to breathe and my chest feels constricted. Whenever I lay down and get up and I start walking, my vision goes fuzzy then I see only blackness, and then the blackness gradually goes away within 10-15 seconds. I know that happens to a lot of people when they get up too fast, but it has been happening to me the last two weeks all the time! And my difficulty breathing isn't bad to where I think i need an oxygen tank, but it feels harder than usual to breathe and doesn't seem normal, and is kinda scary. I'm only 18 and I just moved from California to Idaho, and possibly the elevation may have something to do with it, I'm not sure. Is this something I should be worried about? Or should I just let it play out and hope that it goes away?