Hi, I'm Sixteen And Have Been Sick Since Monday. I

Hi, I'm sixteen and have been sick since Monday. I have noticed I can't stand for more than ten minutes before I fall over. I have a harsh cough and can't breathe through my nose. I Have asthma. About six months ago I started smoking. It was kind of a replacement from self harm. I am quitting smoking. I get dizzy and light headed when I stand up and I cough so hard I nearly puke. My mom is forcing me to go back to school tomorrow and I ride the bus. if I can't stand in my room for more than ten minutes, even holding onto something. How am I supposed to stand on the bus for an hour and halF? Any advice?