I agree with LR and don't be baited into acting in a way you will later regret. Keep trying something different for a few weeks and give yourself time to feel better from all the bad news, blame being thrown at you, and H going behind your back with S stuff. It might be a power struggle and a control issue that he did that. How can you not participate in it but still have a say in S's transition? I'm not sure.
Maybe FM has some ideas because she went through that thing recently with her H about the kids and his apartment.
