What is this? Is it a severe bite or something?

Ok, so lately I have been outside a lot so i get bug-bites. But two days ago I noticed bites (at least i think they are) in areas which are covered by clothing. Then they would itch worse than the regular mosquito bites and would burn like a sunburn if you touch them. I also found one kind of below my armpit that is swollen and red and inflamed. Is this some allergic reaction? Or a severe rash? A bite? I used anti itch antibiotic but it didn't help at all. It seems to get larger everyday and I'm worried about this being serious. I will add a picture of the one bite below my armpit.