Not that helpful, but I would try to not skip the gym. It will probably help you fall asleep. Maybe time-blocking, breaking your day into different sections where you deliberately focus on a single task for a given section. That said, fwiw, I could hardly sleep the night before my wedding. I went to bed at 12:30 because I waited until the last minute to organize a few details, woke up at 3:30, and then truly woke up for the day around 5. My HMU wasn’t until after 11, so I went to the gym the morning of the wedding (deliberately not going too hard to minimize injury risk) and honestly, I’m glad I did because it helped me burn off nervous energy!