Wow! Today was the first time he has ever left the house without kissing me on my check and saying have a good day.
I know how much all those firsts hurt. My H use to kiss me goodbye everyday and sign off all phone calls with 'ok, love you'. One day they just stopped. You are right, he is detaching too. He doesn't know what he wants, and his head doing these little things are 'giving you hope'. This was my H go to phrase whenever I mentioned something (him taking his ring off, him not signing off his texts with 'x' etc).
Pretend it has no effect on you (really hard I know).