When I was very unwell earlier on this year, I would have problems going asleep and staying asleep. I would wake up soon after I'd gone asleep with racing heart, feeling confused, panicking etc. And then near the morning I would continually wake up with a jolt, feeling like surges of adrenaline coming up through from my stomach to my head.
I've made a ton of changes since then so it's hard to know what's helped but the thing I feel really improved this has been going for a run in the evening time. I'm lucky I can still exercise like this, I know a lot of people can't . I feel like it uses up all that extra adrenaline so it's not racing sound my body at night. I still have restless nights sometimes, but nothing like it was before.