Insect bite, started with small pimple on thigh, swelling, pus, subsided. Recurs in various body parts. What could this be?

hi, i am 25 years old, i have a major problem more than 2 month ago i was on my honeymoon in Bali i guess i was bitten by an insect but i didnt feel the bite, it all began with a small pimple in the back thighs and then it started swelling and more reddness i couldnt move my legs and it was filled with puss, i put cream for bites i bought from a pharmacy and took antibiotics its became better each day and the puss came out 3 times till it was dry.. my problem is every now and then it appears to me again different areas also starting small and ending with huge amount of puss coming out, i dont know what to do and 2 months now i am on different types of antibiotics i went to many doctors no one can identify where do they come from and now i have 3 small pimples starting small and afraid to be bigger again with more puss.. any idea what is this? y does it keep coming back and the treatment ?