For about 4 days now I have had a painful mass about the size of a Kiwi if cut down center to make flat. It s just below my bicep and just above the opposite side of my elbow. It feels like there is huge pressure. I tried to drain it with an insulin syringe (clean) but only blood came out and though I filled the syringe several times, it did not seem to reduce the pressure. What is it and how can I stop it ? I have been trying to wrap my arm in a heating pad at night and let the hot water from shower run on it as that takes away a little of the pain for a bit, but then it’s back.