Hey Annika,
sorry this happened to you. I know it sucks when things like this happen. I always worry if this loudness is the new normal. A few months ago I stood in front of an ambulance when the sirens went off. My ringing was louder after that and I even had new sounds and tones than before, but after a few days it went almost back to normal. And after a few weeks I couldn't tell the difference anymore between before and after sirens. So don't panic.

Try to relax and distract you from the temporary loudness as much as you can. (I like to binge watch series and eat ice cream, it distracts me from my fear and worries and sometimes even from the sounds for a few moments.)
When I get exposed to something loud that spikes my tinnitus I immediately take high doses of NAC and the following day as well. I take 600mg everyday anyway and after noise exposure I just increase the dosage for two days. I've read in this forum and in the cited study that soldiers in the US military take it before shooting practice and studies have shown it to reduce the risk of acoustic trauma resulting in hearing loss and or tinnitus. There is little or mixed evidence that it will help if taken after noise exposure but if there is even the slightest chance that it will help and I don't have side effects from NAC, I take it.
Also it makes me feel like I am doing something and it gives me hope that it will protect my ears, even after the noise. I think the working principle of NAC is its antioxidant behaviour and the theory here is that noise trauma induces oxidative stress to the inner ear (someone please correct me if I am wrong). If even part of the oxidative stress is dealing its damage in the hours and days following the noise event, as opposed to instantly on the spot (molecules are not infinitely fast, bodily processes tend to take some time), it would give a window in which to take the NAC (or eat a lot of blueberries?

). Maybe someone here can comment on this more scientifically? But I also don't want to hijack this thread with this NAC stuff.

I just wish I had known about it earlier so I wanted to mention it here.
I hope it quiets down for you soon!

Avocado