I am sorry this is happening to you too. I was in almost the same situation like you a couple of weeks ago. Having anxiety 24/7 tho thankfully my parents are very supportive and took me to the hospital two times. I got a physical check up and everything was perfect. This helped me at first bc I felt safe for a moment but the panic to die came back real quick.They also gave me benzos the first time which I would not recomment but they give a bit of security just having them around. Anxiety can give you all kinds of symtoms and I would advise you not to check them out online since the things you find most often are cancer, strokes etc. and this will proberly make you even more anxious also at your age the chances of getting such conditions are very low (of course no impossible but still) anyway get a check up if you can and best wishes.