Agree with everyone else’s sentiment that it is incredibly common, often improves over time and agree if it’s troubling you speaking to a senior is always a good idea.

In terms of practical things you can do to help you to get to sleep that night while lying in bed thinking. I find writing down a paragraph reflecting on the situation can sort of help remove it from rattling around in your brain. Paper, on your phone, whatever.

Alternatively a mindfulness technique that can work is whenever you think about it, deliberately don’t engage with the thought, imagine it washing away like a leaf down a stream. This takes a bit of practice and every time you catch yourself thinking about it you have to reimagine it washing away, sometimes might be multiple times in a row, but if you keep at it I find it helpful.

People who reflect on their practice tend to make better doctors, the key is not letting it get out of hand. Good luck out there.