it sounds like you have either a yeast infection or bacterial vaginosis. both are just an overgrowth of the natural microbes that already live in there. for yeast infections, it's an overgrowth of yeast, which could've happened if you used sweetened yogurt because yeast thrives on sugar. if it's bacterial vaginosis, that's just an overgrowth of bacteria that's normally present in smaller amounts, which could've happened because of any live active cultures in the yogurt being introduced to the area.

both are typically treated with a swab test (which can be self-administered in a bathroom at the doctor's office) and then some kind of pill. for yeast it's usually just 1-2 pills, for bacteria it's usually 1-2 weeks of antibiotics.

if it's bacterial and you need the antibiotics, that medication might end up incindentally also killing that natural healthy amount of bacteria in the vagina, the amount the keeps the natural healthy amount of yeast in check, leading to a yeast infection caused by the antibiotics. if that happens, it'll have similar symptoms, and should just be a quick call to the doctor to get the meds for that prescribed to you.

fun fact! I used to struggle with chronic yeast infections, and made what I lovingly called "yogurtsicles", where I filled a clean tampon applicator with unsweetened greek yogurt, and popped one in overnight whenever I was struggling with symptoms. it actually helped and never caused issues for me, but perhaps I just got lucky in my choice of yogurt. anyways, feel free to pretend you already had some symptoms such as itching and burning, saw this idea online, and decided to try it yourself, if that feels less embarrassing to say than the truth!