punched with my forehead to a massive jellyfish at Hua Hin Thailand

I punched with my forehead to a massive jellyfish when i was openwater freestyle swimming close to the Monkey mountain of Hua Hin Thailand with a mouths of a canal.
Its underbelly felt partly soft and crusty.
It stung me on the forehead a bit and gravely on my left fingers when I was trying to get rid of this "debris".

location: 12.511108°/ 99.982518° around 4pm Saturday 01.16.2016
I not treated the stings with vinegar and the fingers got swollen until now.
Today I felt a kind of fever and no mood of eating - not sure if this has anything to do with it.