For The Last Few Days, I've Been Having Pain Behind

For the last few days, I've been having pain behind my xiphoid process, especially when I breathe in deeply. The pain also would appear for a bit then dissappear. This would happen throughout the day. Also, my appetite has been affected by it. I also have pain in my back around the same area. Just today, I had more intense pain when it would show up. What could this be?