Extreme pain during sex

I have been having pain during sex for the past one year.

I am 27 year old and I have been married for 6 years and I have a 4 year old baby. So this is not my first time having sex or anything.

I never had any problem until this year. I started feeling extreme pain while having sex. Its like my skin is getting scratched or rubbed dry. I don't know how to describe it and even washing there after trying penetrative sex is painful as hell.

I consulted the doc and went through multiple test for this and the doctor didn't find anything, no infections or bacterias or whatever that can cause this pain.

Finally she suggested some procedure which will increase the wetness of my area and prevent it from being so dry.

But I think I am too young to be wanting such a procedure and overall procedure tends to give me the scare.

Has anyone has this experience and did anything help at all with this. I would really really appreciate some help with this and it's affecting my sexual relationship with my partner.

I started my accutane treatment and birth control pills as part of it from last 6 months which has made it worse as accutane can cause more dryness. But the pain has been there for more than that now. So can't blame the medication fully.

Please share your experiences!