Suggest Remedy For Inflammation Along With Swelling And Itching In Hand

Hi, I m worried. Also typing with my left hand because my right hand is burning, swelling and itchy one week after i snorkelled and contacted either a fire coral r a jelly fish sting. The first thing i did when i got back on the boat is soak my hand in vinegar to relieve the burning sensation. When i returned from my trip, it seemed to be the normal process to go through, some itchiness and redness,,,well since the past 2 days, it got worse ... it spreading from the outer side of my hand and swelling up to my pinky. i started taking antihistamine last night, and woke up now with lots of discomfort and swelling, a tight feeling in my hand, especially when i try to fold it. its exactly one week since... and its feeling a lot worse. could i be poisoned? could it get more severe? what s the best treatment?... thank you for your time. Montreal, CA