After Having Sex I Got A Few Tears In And

after having sex i got a few tears in and around my vaginal opening at the bottom. i am currently in Thailand and have been on a elephant trek where i was in unclean water with elephants and I'm wondering if this could have cause an infection as it appears to be getting worse. symptoms include extreme burning pain when urinating, swollen around the opening and itching. i have had these before and sudocreme usually worked to heal it however this time it appears to be making no difference. getting to a doctor is difficult as i am british so i would like to know what i can do if anything to help myself.