Suggest Treatment For Rib Cage Pain And Shortness Of Breath After Injury

About 6 weeks ago my father and law and I were in a golf cart when he lost Congolese and when down a very steep hill backwards where I fell about 12 feet and my father in law, who is more than twice my size fell on top of the left side of my chest with his shoulder. I m having increasing pain on the front lower part of my chest at the bottom of my rib cage and the mid-bottom of my rib cage on my back. I ve had some shortness of breath, very tired, a lot of phlegm over about 3 weeks or more that is very hard to clear, increased headaches. The pain is manageable but I have been playing a lot of tennis and golf which always leaves me in severe pain afterwards. What do you advise.