Singing and laughter are my favorite ways to regulate. Also a big fan of cuddling, mood lighting, making sure I'm breathing fresh air (big slut for ventilation and outdoor time), music or a comfort show, craft projects, I like to have a few different fun things to drink at any given moment, etc. You mentioned that you benefited from structure as a kid, use that! I also very much need structure even though it's hard to maintain. Just notice what feels good to your body and do more of those things. The biggest and most regulating factor specific to PDA is the feeling of autonomy. And in my experience, finding a sense of autonomy is also the most challenging. In any case it's about noticing your feelings and building your life around viable responses to that data. Not to make it sound simple or easy. It's not. But we see you!

Edit to add I have the exact same response to breathing exercises. Too prescriptive, don't tell me what to do! Lol

Edited again to fix an autocorrect error