When emotions are driving their lives, nothing is rational. That's why it's important to keep your eye on your finances, etc. He really does sound like he's bouncing all over the place.
I know that my xh exhibited some of what you described. The sexathon went on for about 8 weeks and it was every waking minute that he wanted sex or flirting, etc. I think it's the hormones raging and the thought of death. They do think that they are dying at some point because of the way they feel. It's just so crazy and you know what? There's nothing you can do about them, how they are behaving and feeling. All you can do is protect yourself.
Sit quietly, the answers will reveal themselves when you least expect them to. The past is gone, the present is a gift and you need to focus on today, allow the future to reveal itself when it is ready.
