Yesterday 4/29/14. I rearended a propane truck going about 30mph. I dont remember anything leading to the impact. The airbag went off busting my nose and cuttinh my forehead. But im not sure if it was my seatbelt or the airbag that has either bruised or fractured my sternum. I declined medical treatment. But today i can hardly breath without intense pain. I cant move my arms or attempt to stand without extreme pain. Even just sitting is very uncomfortable. How can i determine without going to the ER if its fractured or badly bruised. Any info would be greatly appreciated