I'm sorry that your T hasn't been as supportive around your SI as you would like them to be. It sounds like they don't quite understand SI and the motivations behind it.

You are definitely not an idiot You are very right that it isn't always possible, even with other coping mechanisms, to manage the urges. It takes a lot of time and practice to do so and even then there are still sometimes triggers.

Can you talk to your T about how those comments make you feel?