Long night...

All day yesterday I was having difficult time breathing, by last night it hurt really bad to breath so mom came and took me to the emergency room( not my favorite place i might add). Every time i would breath out there was a sharp pain in my lung, and when i would breath in there was just pressure. Since i had been having problems with my ribs we were kinda worried. When i got there we sat for an hour then they came and took blood for tests, and i got an xray of my chest. The doctor came back and said the blood test indicated that i had a blood clot, and the xray showed some sort of spot on my lung. It terrified me...Over the summer my best friends mom passed away due to cancer. They did a cat scan on my chest and it didnt show any clots but the spot was still there. The doctor said it was a nodule, that could have been there from birth, the only problem is, I've had several chest xrays and they never saw it before. Now we have to wait for three months to see if there is any change in it. I can think logically that it probably is nothing, but with the way my luck has been for the past few years, the worst thing i can imagine comes true. Now i have to wait around to see if my life will or wont change at all... I'm terrified, I cant help it. What am i supposed to do?