Hello, I think you did the absolutely right thing. Well "getting over it" is hard but getting therapy is exactly what I thought, too!
Well, I would have said it more indirectly though, like "I understand you and I am sorry for your past experience, but I can promise you the same won't happen with me, because I love you and I would never intentionally hurt you", etc etc.
Getting fed up is understandable but no solution. Suggest him therapy, and help him while he does this.

Hope my reply was helpful