Hi Lost,
I'm so sorry this happened today. To go from being so happy to this must be so painful!
Everyone has given such good advice about how to stay in the moment even though it's hard. I guess he told you this just be honest. He sounds like a pritty direct guy. Guess he just wanted you to have it in the back of your mind or something. Clearly it wasn't the time for you to hear it. Maybe next session talk about how you don't feel stable enough right now to deal with it. In the meantime we're all here and he did reassure you that when it happens, the process will be very gradual.