The fact that this is all on your mind, that you've plucked up the courage to write this post, and that you are so focused on pleasing her suggests that you are trying to get it all right.
A relationship is a partnership, you have to both want to try, not use put downs to make the other person feel insecure.
It's possible that she is playing out some insecurities of her own with you. But still, IMHO this is not a good start to a marriage. As webgoji points out, there are many ways to truly satisfy someone, it sounds like she's angry at something and using this weak spot to bring you down. You deserve the chance to have a loving, fulfilling marriage with someone who cherishes you and will let you cherish her...and give her oral!!