Yeah, secondary, tough school, something like 50% PP and the SEN crisis is very real. I honestly don't know how anyone teaches in primary at the moment. If I'm honest, it's brutal but I'm a career changer (became a teacher when I was 53) so I still have some energy left for the job.
Completely different tack here, I'm also a union rep, and my HoD is the main rep for the school. This means I have a lot of support in terms of boundaries. For example, I won't be going to INSET because I've got a medical appointment. Sure, I could've scheduled this for the holidays but I don't need to sit in a drafty hall listening to random career building waffle (for the person in charge of that particular training segment) masquerading as CPD. Also, we're very hot at my place about directed time, duties, shared resources, how we respond to the mantra of 'have you called home?', etc. In other words, while I do work long hours, I do this autonomously (I like planning lessons and am left alone to teach what and how I want - obviously, within the constraints of the NC and because I can get the results). I just completely ignore everything I think is stupid.
^^ Point being, although I'm knackered, it's a kind of good knackered, not filled with loads of frustration.
How long have you been teaching? Are you in TPS? Any possibility of an early retirement? Are you familiar with David Fountain's stuff around this, including his FB group?