Hi June, I understand how you feel. My STBX was supported by me for many years through his long custody trial. I felt doubly betrayed when he suddenly decided he wanted to split. My story is in my first thread Surviving the rollercoster.
A 180 can be showing vulnerability. It can be how you respond to him. You want to avoid begging and pleading and try to show a PMA when he is around.that doesn't mean be cold.
Me 52 H 44 T9 M 5 BD 12/11 H split 8/12 OW moved in 12/12 OW gone for good 6/14 We get closer again 9/14 SD 13 Me 4 Grown
Accept what is...let go of what was and have faith in what will be.