Hi there,I have understood your concern and I will suggest you the best possible treatment options.
First of all do not panic.
What you are suffering from can be due to friction, lack of lubrication and or infection.
I will suggest you to abstain from sex activity for a week or so.
Pease seek prescription support for a broad spectrum antibiotic like Doxycycline for 7 days. Use of 
Clindamycin and 
Clotrimazole containing 
vaginal tablets and local ointment containing antibacterial, Antifungal and mild 
steroid is advisable. Use of Lactic acid containing vaginal wash during the bath time will be of help.
Please get sex counseling done for future,with reference to safe and protected sex, this will help to prevent unwanted 
pregnancy and STDs.
I hope this answer helps you.
Thanks.
Dr. Purushottam Neurgaonkar