Vanilla/no libido girlfriend... What to do?

Hi /sex

Just going to jump right into it. Me and my girlfriend are in our early 20's, and have been together for about 4 years, living together for the last 3 years. My problem is that not only is she very vanilla when it comes to sex, she also has a very low libido. I've talked to her about both of these things, but the libido is nothing she can really change, and the vanilla part she is not interested in changing... I love her but it's getting to a point where I am watching more porn then I did when I was single. Now, I understand that not everyone wants something up their butt, or want to pee on their significant other, but she doesn't even let me lick her ass, even though she knows it's my biggest turn on. I've tried talking to her and trying to get her to tell me her fantasies, but there really seems to be none. And she does know that I have a crazy high sex drive, and the fact that we are almost always naked when we are home does not help at all. She does help me out if I ask her for a handjob, but she only does that because I asked her to, not because she enjoys it or because it turns her on... I feel bad asking because of that reason, and only do once or twice a month at max. I feel stupid and a little bit like a asshole, since that's the only thing I want - kinky things. But I don't know what to do. I want to spend my life with her, but at the same time, I have a billion and one fantasies and it doesn't seem like she'll grant them anytime soon... Any insight on what I should do?