It's quite possible for vaginismus to only occur during intercourse. If you're fine with fingers but not with intercourse, it's almost certainly psychologically based (and involuntary).

I wonder if this article might give you some ideas:
When Sex Hurts: Hope for Those who Tense Up Due To Vaginismus

I've dealt with this issue myself- only during intercourse- and it gradually got better over time. It is still present occasionally, but not to the extent that it was. I didn't do anything special to change it, just let it settle down over time.