What to expect at physiotherapy?

I have tmj/d (temporomandibular joint dysfunction) and it's been getting worse over the past six years

I have an appointment for physiotherapy coming soon and I'm really nervous as I'm not really sure what to expect?
I've done a bit of research about some possible relaxation activities that they might do, but I was told they might do an assessment on my full body?

what kind of things should I expect for them to do? and is there anyway to worry a bit less?