I'm on doxycycline and now I have a yeast infection. I'm on meds. Now I realized I have chancres on my vagina? And one side is swollen, is this herpes

See an OB/GYN. You have several problems in progress all at the same time. Unclear why you are on doxycycline, but that is what has predisposed you to yeast infection. If you have genital herpes that may need to be treated aggressively and you will need prescription. Also, you may have been exposed to std and should be tested for hiv, syphilis, etc.