Aged Person With No Sex For Long Time. Now Cannot Insert. Feel Tight, No Yeast Infection. Did Obgyn. Suggestions?

I am 66 years old. I had gone for 25 years with out sex and very little masturbation.

After that length of time I started to masturbate, again, on a regular basis. I still have
not had sex.

About a year ago, when sex was being thought of, due to the fact of wanting to get married, all
of a sudden... I could not insert anything into myself. It was very painful and just feels so
tight.

This literally happened overnight.

There was nothing like a yeast infection or anything and I still cannot insert anuything
larger then a nickle in diameter. Even that is painful.

I go to my obgyn in 2 weeks for an annual, and believe his speculum will not go in now.

Any ideas?