Hi, what is it that bother you about not being able to perform ? If you think everyone is normal , it's better to evaluate. Also, if you say you are having orgasms that means you are able to enjoy sex. Now, not been able to have intercourse has lot of possibilities and conditions and the most common are these two. 1. Voluntary or involuntary tightening of vaginal muscles or 2. Vaginal drying leading to pain.
At times you may require hormonal assessment as well.
Sometimes things are more in mind then actually on the body.
Next Steps
Try to consult a gynecologist for the same. And he / she will be able to help you.
Health Tips
Try to use water based lubricants. And see if it helps.