So has she tried the patch? I wouldn't go near the shot with a 10-foot-pole, but the patch seems to work fine (though we always use condoms) and my libido is pretty good. The bad thing for me is that it makes me nauseous and actually throw up sometimes (once a month), so I'm thinking of changing or getting off BC entirely. But at least I still want sex.
I'm under the impression that a LOT of women can't orgasm from penetration alone, including me. Is this a big hang-up for you (if so, why?). I always need clit stimulation, and that's not a problem with my bf. Orgasms in general aren't an issue for us... sometimes I cum, sometimes I don't, but we don't worry about it every time. Try not to stress about it if she's fine with oral climaxes only. Also, does she come from penetration combined with oral? (E.g. when you reach around while inside her and play with her clit, or use a vibrator while you do oral?).
Btw, just because you have a dick and want more sex than she does, doesn't MAKE you a dick.
At least you're honest and loving about your approach. Have you told her all that stuff that you told us? And damn, you already have the ring to ask her to marry you? I'd say try relationship or even sex counseling first, to make sure that you guys will be compatible in the long run... at 21 I hope you aren't in THAT big of a rush. Straighten out these issues before you think about the long-term.