How Can Yeast Infection With Trich And Itching Be Treated?

hi,every since i been diagnose with "trcih", my vagina hasnt been the same..when i was treating the std, i notice i have caught a yeast infection, and my vagina was red and swollen..so later my doctor gave me cream to take for the yeast and antibiotics, for bacteria infection. my symptoms cleared up, but several days later i started back itching and now i have thick white discharge..i wonder why, is the yeast still exist in my underwear, or is it a bigger problem than that? what should i do?? keep taking medicines??, and hope it doesn't come back this time..