“Back ”

I’m having back pain. I’m 36, I’m taking Tylenol extra strength as needed and the pain relievers my dr. Prescribed only when the pain is almost unbearable. When I went to my general family dr. Today and told him about my pain in my back. My doctor only put a cortisone shot in the spot that really hurts me the most and not in the other areas. He also did one in my shoulder. But since he put the shot in that one spot, I’m feeling all the other places that hurts me in my back. What does this mean and what do I do? Why am I hurting the other hurt areas in my back. I usually feel the other areas when I have stood too long and or sat too long. Sometime I feel a couple and then a few and now I’m feeling them worse.