Class Act--I am a true Sag and have had my share of men who just didn't get it. The fact is that she felt trapped and needed to break free of you. Now how does anyone make something like that palatable to hear? Particularly if they care about you at all. Sag women are instinctual creatures, for all their tendency towards being high minded and scrupulously honest. You've been hurt. Horribly hurt from how you convey your feelings and your Aries ego has taken an enormous hit, as well. But don't compound your agony with humiliation by attempting to get some feeling from her that she may be incapable of giving you. And be honest with yourself. That sort of brutal honesty that I'm sure was an important part of your relationship with a Sag woman. Admit that on some level, you want this all to make sense and you want her to help you make sense of it by teasing out some of the same woman you fell so deeply in love with. You don't want to get back with her and that's for the best, because while she will likely always have tender feelings for you (the sort that make her think of you on your special day/birthday) she will always associate you with being reigned in, having clipped her wings. She's done, because the woman you'd end up with if she stayed or perhaps came back, would be unrecognizable to the both of you.
If it helps any, I stumbled across this website while researching personality traits of Sagittarians. It has been several years since I'd done so and needed a reminder of my own fabulousness. I am well over thirty and have enjoyed a life of torrid, passionate affairs where I bolted as soon as my lover tried to move his clothes in my closet, or started dropping hints about how nice it would be if I gave him a key to my house. Sag women are capable of inspiring intense, almost worshipful love. Case in point--you, my dear Class Act. Just remember--a Sag woman detests any sign of weakness in a man. Tears might turn us on, but for all the wrong reasons. You don't want her guilt, because that's what those tears were after she broke up with you. For herself, dear. But guilty tears, nevertheless.
I don't know if this will help and don't know if you've gotten over the wild one, but be kind to yourself. And try not to make any decisions that are not based on being honest about what end result you desire.