Hugs.... Who knows whats going on in his head. It could be anything, nothing...
You don't HAVE to do anything. Just because some one says they love you, doesn't mean you have to love them back. You are completely free to stick to your decision that the relationship is done, if that's what you want.
You could tell him: Back up, jack. There's no working this out right now.
You could tell him: Love and miss you, too.
You could tell him: Love and miss you, too, especially the drinking and Dr Jeckyll Mr Hyde swings.
You could tell him: Sorry, I can't talk. I'm getting ready to move to Antarctica.
All you really need to know is what you want.