One good term to understand with waking up in the middle of the night, night sweats, etc, is; circadian rhythm. You can find more info under that type of search.
When I’m extemely stressed, usually through working quite hard, overtime, I wake up around three AM, with sweats, and have a hard time getting back to sleep. Right before that, dreams are very vivid, usually specific as to stressors. Also, being femme, it correlates to hormones, especially mid-cycle time.
What helps is getting to bed before 10 pm, exactly like I’m Not doing here, and not having too many stimulants (coffee, tea, etc) past late afternoon. OK, going to bed now…