right arm/ hand swelling

Okay, has anyone ever experienced this? Last Wednesday is when the first picture happened. I took Benadryl because I thought maybe swelling and redness could be an allergic reaction & id wait until the next day. Well next day came and it was still swollen and red when I used my hand a lot. I started feeling nauseous so my sister picked me up from work to take me to a minute clinic. From there I started throwing up uncontrollably and was admitted to the er. They did blood tests and a ct scan and only found I have a UTI which could explain the puking. But ever since, I've lost strength in this arm and if I use too much I have to give it a rest, kind of like I've just worked out feeling. I'm calling the doctor tomorrow, but has anyone ever experienced this? It's not gallstones, I'm getting circulation, I have no cuts or bites on my arm or anywhere else. I've also been getting these awful throbbing headaches in the back of my head (I don't know if they could be in correlation). Thank you!