Runners, tips for early morning races?

For those of us who run, how are we managing races that typically start early morning?

My heart is not great until midday, until I’ve had enough salt and water, so I’m struggling with races that typically begin at 9am. I struggle to get enough water down me without needing to pee during the race, and combine that with nerves and bad sleep, my POTs is really holding me back.

Super sad when you spend so many months training only to have your condition hold you back :( any tips appreciated!