How long has it been since you sent the e-mail saying you were struggling? It's possible he's just been busy or out of town or something. Or, like Luna said, maybe wanted to talk to you in person about it? Is there a time when you're due to meet with him along with your son?

It's also possible you misinterpreted his response about your son's homework assignment as snippy. Like maybe he just was trying to be enthusiastic about it, like, 'This would be a great thing for him to try!" So when you responded the way you did, he was concerned that you might misinterpret other e-mails. Would it be possible to talk to him on the phone?

Also, I think it would be helpful for you to get your own T, if possible.

And I know, from experience, that attachment to a T can be really difficult, especially if it's not your individual T--I'm going through that with my marriage counselor right now (both he and H are aware of it and OK with working through it).