What was it?

I know there is the big problem of HIM not wanting children. But HIS behavior the past couple days -- so mean, hurtful, and angry -- makes me think there's more. What was it? What about me or loving me made HIM so angry? And what caused HIM to turn so fast? HE was claiming HE loved me the night before HE moved out. But how does one love and say such horrible, mean things? and how does one end a relationship without a backwards glance? and without an ounce of sadness?
I'm baffled and hoping for closure -- even though I know that's a self-helpy bullshit word. I still want it. I want to autopsy our relationship. I want to know what HE liked and what HE didn't.
Did it bother HIM when I didn't wear a bra at home? Maybe I got too comfortable?
Maybe I'm too demanding and expect too much?
HE said I loved my pets more than HIM. Not true, but how awful to feel that way...I don't know exactly what I did to make HIM feel less loved than my cats, but I wish HE could tell me. I never want the person I'm with to feel less loved than my pets.
I texted HIM at 3:00pm and said something like "does it feel weird not to have spoken to me today? It feels weird to me." HE said -- "no, not at all. lol"  After seeing each other every day for months on end and speaking upwards of 20 times a day -- not speaking to me doesn't feel weird? I'm that forgettable?
As if I asked Are you hungry?
As if I wasn't asking for reassurance that this is hard for HIM too. Evidently, how upset I am is inversely proportional to how un-upset HE is. 
So, tell me, internets, what was it?