This is a known unknown. There is no way of knowing what he's thinking. Is it possible that he's having second thoughts about divorcing? Not very likely, but maybe. It's more likely that being nice to you eases his sense of guilt.
Regardless, try best to not let it affect you. Wayward spouses are all over the place emotionally. They could take a positive step, then take two negative steps.
Wish you strength. You've got a long road ahead.
Me: 50, MLC/WW 45 Young kids Nov 2015: BD1 Apr 2016: BD2 Jan 2017: W filed Feb 2017: D final