Well, I'm a girl and I love giving oral sex, I can't understand girls who hate it :-)
Having said that, it does seem that it is far more than just an oral sex problem - so she isn't interested in any other form of sexual contact? If this is so, then I do think this is a serious problem. Some girls simply are NOT interested in sex, and if you are, then you aren't going to have a relationship that works. I know a guy, now in his 40s, who was married for 20 years to a woman who refused to consummate the marriage or do anything to keep him sexually happy. He put up with it for many years because he loved her, and had sex with other women on the side, but in the end he gave up and left her. I don't see this as the man being unreasonable - sex - and often oral sex - are normal parts of an adult relationship. To bury her head in the sand and act like the relationship will be fine without it is ridiculous. It won't.
I speak from experience. I spent a the first half of my twenties with an older man I loved but who was near completely impotent. That is, impotent enough that he couldn't manage to have intercourse with me, but not enough that he couldn't receive oral to completion. Fortunately, I like giving oral, and he was prepared to pleasure me in other ways, but it did not make up for the lack of a full sex life, I was extremely frustrated and in the end stopped fancying him at all. After all, how can you continue to see someone in a sexual way when they fail to engage in a full sexual relationship with you?
I don't think you are unreasonable to expect SOME kind of sexual relationship with her, in which you get sexual pleasure. Those girls who don't like giving oral on here, may well be compensating in other ways, through intercourse, hand jobs, etc. If you aren't getting ANYTHING from your girlfriend, after 2 years, I think I'd walk away from the relationship - because at this late stage, it really isn't going to get better.
Plus, she obviously doesn't like the idea of giving oral or having sex, so if she does give in to stop losing you, just how is that going to make you feel? Nothing is going to turn her into a girl who enjoys these things - she is never going to want to do it, and you would just have a constant battle on your hands to persuade her against her will. If you actually want a relationship with a decent sex life, you have to get out now and stop wasting your time.