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Dryness of vagina
was due to inadequate lack of lubrication so for that you can hence forth use a lubricating jelly like K-Y jelly
to apply locally to vaginal opening before coitus.
The pain at the vaginal introitus (start of the passage) is due to abrasion caused during sex.
This abrasion is causing pain and burning during passing of urine for which you can locally apply betadine
ointment which will help heal the injury