Need help. bug bite, or worse?

i am 18 150lbs 5.9'' i woke up the other day with what looked like a pimple on my back(i could feel a slight stinging so i looked in the mirror) i disregarded it washing it with soap but later that day i noticed being paranoid looking again the thing had laid down as in its turned the skin at and around a yellowish tint i had put some iodine peroxide on a bandage and put over the spot and taking the band aid off for a shower i noticed the spot was emitting small amounts of a transparent yellow liquid im not sure if this has to do with the thing but it seems small red bumps had appeared around the area on my back not many but about 5 or 6. please if anyone can help or tell me what it is or what i should do i don't want to not act but i don't want to act on the wrong thing so if anyone can help...