Affair discovered 3

[STH17]

The 8:30 thing for son tomorrow is a school evaluation near W's parents. I felt blindsided by that and we ended up in a typical argument for us. My mind races with scared and weak and angry thoughts, things I think I can't or shouldn't say, and W gets impatient with my silence, so I start talking but my tone is angry because I always feel like she is criticizing me for my silence. And I don't think I can just hang up because I feel like I have to respond but don't know what to say.
She asked if I wanted to come with to the evaluation. Son started crying real loud because he wanted to make cupcakes. He sounded really distressed. I told W to take care of him and call me back. I tried to cool off during that time. When she called back she asked if my main concern was having equal time with my son. During the first call I said she was making a decision without me about son that would reduce the time I could spend with him. So I confirmed that was my main concern. She said she didn't even know what a schedule would be for school. I asked if she wanted to put son in school just so someone would be watching him or because she wanted him in school. She said he should be in school because he needs the stimulation. I reminded her that this wasn't even a consideration for her a few months ago when she wanted to move out. (She had said he didn't have to be in school since he was only 4). I think she was just quiet after I said that.

We didn't talk about the library books. I'm not taking them even though I was planning on going to the library with son this weekend. She wanted the W2 and tax return for enrolling son in the school. Is that really something that's needed? She's looking at a public school, we had son in a private school last year. I thought she might want them to work on divorce papers. Or gov benefits?