What Causes Pain In Breast While Deep Breathing?

I fell yesterday on my deck--I am disabled post cancer and have arthritis everywhere esp. in knees. I fell over the edge of a chair. I was watching a 4 year old relative at the time alone. I was able to get up with the help of her and the chair but I have a persistent pain under right breast area that hurts when I deep breathe. i have CHF, pulmonary hypotention, asthma and cOpd on oxygen and fall often. This is a new pain altho I have had a collpased lung after cancer surgery and O2 sat is ok. Really deed breath pulls on the rib cage as if another bruise.