Got Bit By Some Kind Of Bug, I Think Flying

got bit by some kind of bug, I think flying insect, along a stream in the mountains. One hole in the skin. The skin is red, warm, and is spreading. it is about the size of a flattened tennis ball on my lower back and is spreading to my groin where it is swollen and red. Starting to get hives as well. Happened about yesterday around 5:00 pm.