Nothing to be ashamed of, bro. I am the first to say I'm whupped for my wife, but she is worth it, and reciprocates with love, respect, and compromise back to me. That is the way things work in a solid, healthy relationship.
I would not let it go without at least having a talk with her about it and get her reactions. Maybe she has no idea that you feel this way, and meant no harm or foul. Maybe she did know, but didn't care, because she thought you'd be okay with her doing what is best for her (if this is the case, point out how selfish that is that you had to compromise and she did not). You need to get this cleared up, bud, don't let it stay a mystery. Whether you admit it or not, it will gnaw at your guts, and cause you to blow up next time something little happens, when she is totally innocent of anything but being unaware that her choice may have hurt your feelings. Or, it may result in you not being aware that she really doesn't care for and respect you the way you do her, and that can only lead to the uncomfortable and miserable day when you walk in on her with another guy.
I know that hurts to think about, but little signs are the first indicator of a problem... Sorry...
Talk. If there is any advice that I can give you, talk. Communication is 98% of a relationship, the rest is just being good in bed
. Don't let this one slide, because you'll be inclined to let the next one, and the next one after that, slide, too. It is not fair that you should let things slide and eat you up inside, while she gets a free pass to do what she will. You both need to agree on decisions, and to compromise for each other for the benefit of you both. If that means you both agree that she goes to the other school, then fine, but at least make her realize that it presented a problem for you that she did so, and that you at least expected her to talk it over with you first (that is only fair, right?). A relationship where you do what you want, when you want, without considering your partner, is no relationship at all.
Open, honest communication. No secrets between lovers, even if you think it is for the best. It NEVER is for the best.
Oh, and don't tell her you'd gotten on here for advice from your diesel truck buddies. No secrets, but that doesn't mean you have to SPECIFICALLY mention everything!!!