I m a 46 yo female who went back to boxing after a 4 mouth leave due to travel/work. About 10 minutes into punching the hard bag, I felt my heart beat quickly and hard in my chest. It actually hurt to inhale 1/2 way. Later that night, I had pain in my left collarbone area and across my chest. I slept sitting up for 3 nights and then was only able to sleep on two pillow on my back. This happened 8 days ago. Today I feel also like me. However, I feel tired when I am doing normal activities like walking up stairs, lifting laundry, etc. Normal breathing is ok, but to take a deep breath still hurts slightly on the left side of my chest. Can you tell me what happened?