There are exercises one can do to help alleviate the symptoms of this problem. One method I know of is to do kegel exercises (squeezing the pelvic muscles you use to stop the flow of urine when urinating) while inserting a finger. Do 20 of these every night when your in bed, and gradually work up to two fingers, and then three if possible.

This gets your body used to having an object inside of you, and trains your mind to associate the muscle squeezes with an object inside of you as nothing to worry about.

Basically, vaginismis is when your kegel muscles reflexively seize up (to a varying degree) when an object is headed into you. So, doing the exercises, like I said before, helps to train mind and body to relax more when something is there.