Hi,

You give a typical description of a condition called Vulvitis or Vulvovaginitis. They can be because of infection, bubble baths, sprays, tight clothes. You are giving a description of all the factors here.

So it is important to the following test to arrive at a reason for the vulvitis and treat than giving medicine for all.
CBC
Urine microscopy
Vaginal examination with microscopy of the discharge

All of the above are important to specifically treat the condition.
Avoid intercourse for sometime
Do not use perfume over the parts of the body
Wear cotton undergarments
You can start with over the counter candidal vaginal cream. But it warrants an examination by doctor nearby if it is not cured in one week.

All the best

---