Waking up suddenly in the small hours with a head full of stuff is a sure sign that you're overstressed.
Dreaming is the primary way our brain processes the challenges of the day, but it can only deal with so much at once! If your heart sinks when you look at the clock, you're not alone ... many, many people experience this, and especially at the moment. Of course inactivity, isolation and the resultant late night screen binge, fridge raid and tipple or four don't help matters - they're not helping you 'switch off' even if it seems they are.
Boring I know, but getting into good habits to destress in the evening will help to a degree. Stretching, talking things through or writing them down, going to bed before you nod off on the sofa (to sleep, not to scroll on your phone obv) will help, but if you're still waking up at 3am with the world on your shoulders, it may be time to think about how you manage other areas of your life causing you difficulty. Problems seem so insurmountable in the middle of the night, and of course some issues just can't be solved right now, but small changes you can make in your thinking and behaviour around the things causing you anxiety can really lead to big differences in how you feel over time.
Take a small positive step, then another, and another, and you might be surprised how easy it is to leave that sinking 3am feeling behind you.