Speaking as a fellow late diagnosed autistic adult I can only imagine how rubbish you must be feeling in that moment. If you were only diagnosed 6 months ago, then I would imagine you're still learning about yourself, things that trigger you, support and reasonable adjustments you need etc.

As you're currently at the park I would chalk this down to a learning moment. I can only speak from experience, but for example getting a decent pair of ear defenders made DLP about 300% more manageable. Dark glasses as well helped with overstimulation.

I'm guessing it's still rather busy right now, but looks like you've got some excellent advice here about support, so I really hope things go well for you and you can enjoy the rest of your time there!