Pax, I think it's human nature when you near the end of something to look back on it a little more fondly than perhaps it warrants. Also, life/death stuff that is all around us now makes us more wistful and melancholy than usual. I think for me, I almost feel a Stockholm Syndrome thing by my inability to get away.
When those times come, I try to remember the hurt and the pain. Because that is the reality now. Yours not only cheated and lied to you, he hid money, lied to courts, tried to make you have to pay him, treats you like a plague carrier when you switch the dog. Not a good guy there and from what it sounds, no sense that he's gotten any kinder or more decent.
When I think about my life and what excites me, it is always a forward-looking thing now. Always the place I'm moving, my new home, what I will do there, how I spend time, the people I will meet. It isn't the past and it isn't someone who taught me he's untrustworthy, disloyal, and unfaithful.