Suggest Treatment For Pain And Swelling In Arm After Pertussis Shot

im 20 female and in november i got a pertussis shot and ever since i got it i been having severe pain in my uper arm, and swelling, tension, having trouble moving it. i tryed ice, pain medication, steroids, elevating my arm, sometimes it will work sometimes not but no matter what the pain always comes back. Whats wrong?