How Can Swelling In The Feet Due To Wasp Sting Be Treated?

I was stung by a wasp the first week of October. My foot was swollen at the site of the sting. A few days later the inside of my mouth felt like I had chewed on it all night long, but I hadn t, I also got a red rash under both arms in the pit area and part way down the sides. I was given some prescriptions at ER. Things seemed to be better: swelling went down, rash disappeared, mouth returned to normal. However, now I have a couple of blotched on both legs that feel like they are silver dollar size lumps under the skin and my legs and feet or swelling, more so on the foot that was stung but the other one is showing these slight symptoms as well. I have been taking Benadryl but the swelling isn t going away. What can be causing the problem