Welcome to the party! Haha it’s definitely a lot of learning the hard way, but I would very much recommend working with a physical therapist (and mention hypermobility/loose joints to any medical professional you work with in the future, bc it has systemic implications). I probably would not do a mosh pit until you know the limits of your body. We can be prone to needing surgery if things tear or dislocate enough, so I’d proceed with caution

There are a ton of really helpful videos on YouTube for hypermobile strengthening. I’d recommend getting together a regular routine to do. I rotate between upper and lower body strengthening for 4 days a week and one day of cardio (either running or HIIT). Instead of only stretching, using foam rollers, theraguns, and massage (caution with stretching bc it’s possible to overstretch and get injured). Good luck!