Don't worry about feeling low. Know that it will pass quicker than you realize. Probably has already passed by now.
When did she make you dinner? I keep up with your threads and don't remember that. Refresh my memory please. I think that her moving will be good. Having these strings attached produces weird situations. The less of these strings to deal with the better.
As for cancelling the dates, that is OK. I can see how you don't feel up to it. I think you should keep moving in that direction though, but who am I to talk. I have not done this at all and would feel as if I am "cheating" on ex if I did this. My therapist told me that I need to date a little bit and that it would be good for me. She told me that I am divorced and I don't owe ex a commitment. I agree with her. I know how you feel though. No one at all interests me. I think having social interactions with others is healthy though.
I am happy to hear that your father doesn't have to go through chemo. That is good news!