Hi Meow_machine! Glad you've had your first appointment. When you next see her, ask about the diagnosis. As we're both in Australia, I'll say to you that my OT did outright say to me that yes, I do have SPD.

I'm hypersensitive on everything except visual. I do the brushing, but the advice from my OT was in the morning, before you go to bed (because it helps with sleeping) and then otherwise when you're going to do something that will be stressful for your system and after you've done something stressful. I think people vary in how effective they find it. I find it quite effective for overall calming down my system. My job involves presenting 1.5 hour sessions to school groups of up to 100 kids at a time. I brush after it, because I can often feel jittery/wired afterwards and it gradually calms me down. When I have to deal with working at heights, it works to help keep me from falling straight into sleepy tired because I've overstressed my vestibular system. Nowadays, I mainly do it when I know that I'm going to have a sensory stressful day or after something stressful.

I've found yoga also very effective for overall calming down my system. I have a box of various shaped/sizes smooth rocks/marbles that I bought from the 2 dollar shop that I can run my hands through, that feels nice. I have a squeezy ball that goes with me almost anywhere when I leave the house.

Hope you start to make some headway with this!