Hope you are managing at work, Clarrie. Glad to hear dh is out of it for the moment.
I think he loves OW. He told me she made him feel happy every day.
When you've been married to someone for 20 years, of course it's exciting to have a new relationship. And it being a Romeo and Juliet situation, where it's not allowed and you have to romantically steal tiny moments together, makes it all the more exciting.
It is the "hearts and flowers", "spring is in the air" infatuation you get at the start of a relationship. Of course that makes the normal everyday life you have with your partner after 20 years look relatively bland by comparison. And when you're having an affair, your subconscious is wildly trying to justify it so that you can tell yourself you are not the bad guy. Some cheaters do this by deciding that their marriage was dead. Others decide that the marriage was never that exciting, and that the OW is their first real experience of love - it being so romantic that that trumps their faithfulness.
Almost all of the stuff that he comes out with now will be this kind of justification and teenage romance stuff. You don't have to take any of it at face value.
I let my exh get on with his new love affair. A few years down the line she found a new love of her life and cheated on exh with the new guy. Now exh has a new love of his life, though that also seems to be getting a bit tarnished already. So my relationship with him lasted 15 years longer than his with wonderful OW... guess I win!
Just because your dh fancies this new woman, that does not mean that she is nicer than you, or that your relationship was crap, or anything of the kind. It means that your dh was unfaithful. That may be because he didn't value your marriage as much any more. Or he might only now be appreciating how much he values it, and what a dick he's been, now he's mucked it up. You will know how much of a dick he can be.