I've been getting severe heart burns and acid reflux and now when i yawn or breathe in i get this sharp pain that starts in my abdomen?

GERD: Acid reflux, or GERD, is a very common cause of symptoms similar to those you're describing. If your symptoms have been persistent, you probably need to see a doctor for treatment. In the meantime, try an antacid such as Tums (calcium carbonate) or Mylanta, to see if it gives you temporary relief. You may need to follow anti-reflux measures and or be on medication to get this under control. Good luck.