Hi I think you should go for evaluation first. Get a thyroid profile and prolactin level and a ultrasound done to see uterus and ovaries to find out the cause of irregular periods. Also get a serum FSH level done to see if you are going to attain menopause. Dryness can be due to low oestrogen level due to ovarian dysfunction. You can use some oestrogen cream locally after consulting your doctor. Hope it helps.