I am not trying to speak for Frank but I am sure he would say you have not done anything wrong or anything that made him feel worse. Please don't think that you did.
Frank just needs some time alone right now to figure out what he needs to do to best take care of himself. He'll be okay - and he'll let us know he's okay - just as soon as he works a few things out in his head and heart.
I just wanted you know that I really am sure you didn't do anything to upset his situation further.