as you was married before a month and you are facing a problem which you described.
Not any doctor can come to decision for the actual reason about this problem.
1. One you should have to find out what happens exactly when you insert?
2. Try to understand your wife and also make her to co-operate what she got uncomfortable in it?
3. If you find something try to solve your self or help of good sexologist
4. if still you facing problem visit her to the doctor..
Dr. Nikul Patel