Is it horrible for me to hold off until she's ready?

LOL. I don't even know why she is still with you. You stopped giving her oral because you "didn't think it would be appropriate if she didn't do that for you"???? OMG! Who do you really think you are kidding? If you intend to get married you may want to try some honesty in your relationship. You may want to just up and admit that you don't feel she deserves it unless she is giving it back. Be sure you tell her that you don't care if the act disgusts her, you are going to act like a child and punish her. You consider it a "hope of you sharing intimacy together"??? You need to stop talking like a relationship help book because you are very transparent. She does not like giving blow jobs. Many women don't. If that is a deal breaker in your relationship, you don't have a relationship. Let her find a guy with more cl.