You've already tried several tablets without relief, and the area is now sore from scratching. That combination needs an actual look rather than another product guess.
Next Steps
Book a gynaecology visit so the skin can be examined directly. The right approach depends on whether this is an infection or simple irritation, which needs an exam to tell apart.
Health Tips
Skip scented soaps and tight synthetic underwear until you're seen, since these commonly worsen this kind of irritation.