Coming here is already a good thing to be doing. It will educate you about this whole thing(unless you already are of course!). Also, it was a very good idea to point him in the direction of a therapist.
So, you've already started
Two of the best things you could have done. These kinds of things mean you're empowering yourself with the knowledge you need which will enable you to be able to be an understanding/compassionate girlfriend. And if he can see a (good) therapist, that should give him the guidance he probably needs. Also though, it can be very confusing/dissorienting for us partners to be with a survivor and so if at any point you feel that things become very difficult for you, it may also be a good idea for you to see a good therapist too.(unless you already do!)
I'm not surprised it's shocked you, it IS very shocking stuff and brings up a tone of emotionally complex feelings when we find out the man we love has been abused in this way. It is a good idea to allow all of those feelings within yourself too. It can be so hard to know how to further approach talking about it together. I'm not sure I'm doing that well with it still :rolleyes: . But I do know that acknowledging all our feelings is a good place to start.
It does sound like you're already doing all the right things...