I have 2-3 yellow fly bites on both of my feet. I have had these bites for 24 hours now. My feet are red, swollen half way up my calf, warm to touch, tender to touch, they itch really bad. It hurts all the way up my leg when I walk. The toes on my one foot actually look a little purplish in color from all the swelling. Benadryl, anti itch spray and hydrocortisone cream are not working. I feel slightly chilled. I have the inside temp at 68 degrees and I am having to wear a hoody. These are not the only yellow fly bites I have had. I have several up and down both lower legs from about 4 weeks ago, and they are still scabbed and itchy. The more I walk the harder it gets to walk. Should I se a doctor or should I wait a while and see if it gets better?

Owing to your description, I would not hesitate to see a doctor, in fact I think you should go directly to the hospital. If benadryl isn't helping, as it usually does, then you are having an extremely dangerous reaction to the venom.