Suggest Remedy For Fever After Being Stung By Sting Ray

i am in mexico and was stung by a sting ray on my toe. the doctor prescribed celestamine and gave me a shot of dexametasona sp? I took the celestamine for 3 days and discontinued per instructions however 3 days later I have developed a fever and there is slight redness around the sting area. I still have some of the celestamine left ans was wondering if I should continue taking it. i was taking 3 a day for 4 days. Thank you for any help.