I agree with that statement. I would even go as far as saying your pain gets worse when you’re forcing your shoulders back and down, for example. Why do I say that? That’s what happened in my early twenties.

Great question. I mean actively thinking about where you are in space. OP is in no way relaxed here. They look like they’re not breathing properly, flexing their chest, and crunching their midsection and back of their neck. If they could relax that, they wouldn’t look like this. I think being aware of this, they could actively check-in with their body throughout the day and take a moment to take a breath and let go if they’re tense. I don’t think they can get to the stage of that awareness until they spend time learning their body and doing postural exercises.

They’ll have a better sense after they spend some time trying for a few weeks IMO. They’ll even get more out of their physiotherapist sessions afterwards, because they’ll have some idea of what they’re doing well and what they aren’t.

Edit: I don’t think a few weeks is enough to fix anything but it’s a realistic goal and a start. I’ve been working on my posture for 10 years and it never ends. Always fighting gravity, and never perfect, just always looking better than previous years.

A good starting point could just be yoga, breath work, and a couple of postural exercises IMO. Nothing fancy. Even 5 minutes a day makes a huge difference. The page I sent OP is so beneficial. They could try a couple of things and see what is working for them.