A big part of everyone's life is stress, and how to manage it. I got out of school just a few years ago (OK, maybe more than a few years ago). The only course that I still use as a base for managing stress has been...Stress Management. It was considered a filler course, something to knock out a few hours of credit, nothing really important, just something to do and have some fun with. Some of us even managed to get into a little bit of trouble...in a course called Stress Management. I'm going to refer to stress management as SM - no not that other thing, easy now!
You can search for how to manage stress and there are more than a few solutions that you will be presented with. I've searched and researched for several years, and when I come across an article that looks interesting, I'll read it. Usually I'll pick up something that I've not seen before (Box Breathing anyone?).
What I know that works for me is this. I can exercise all I want to try and deal with whatever is stressing me. That will generally help for a while. But it's the waking up at 3 dark-thirty and the gears start grinding, that's when stress can really show up for me. I'm not busy doing something to take my mind off the stressors, it's quiet and if I'm not careful it'll be time to get out of bed and start the day before I know it.
In that SM class we were taught to be still, and to breathe. The basis of what is taught today, it doesn't matter the modality, is to be quiet, and breathe, if only for a short time. I've read that the military (thank you all for your service, and our freedoms, the world over) uses box breathing, and also a mantra that goes "don't think" repeatedly. I have found for me that that works wonders. That combination is simple but effective. The way I do it is I box breathe (if you want to know what that is, click here or here) 4 or 5 times, slowing down and focusing on my breathing, then I just breathe normally. Then on the inhale I say to myself quietly the word "don't" and on the exhale "think". I do that half a dozen times or so and if I find I can't clear my mind, I start the process over. This is what I do that seems to work for me, but there are many other breathing techniques (I've tried many, and they all have given me some benefit) that you may want to try out.
Other words and phrases I've used are: (Be) Still, calm, quiet, peace, blank. I've also shushed myself like one shushes a baby. That sound is very effective. That can be combined into a breathing exercise, inhale, hold, and exhale through your teeth (the shushing sound)
I also find that during the day there are stressors that pop up, and breathing techniques are very helpful in calming down and refocusing. It can be box breathing or just taking in a breath, holding it for a bit then forcefully exhaling it out. Doing this several times helps me to recenter. Sometimes I'll try and take a few minutes and do a deeper inhale, hold it for a bit, then slowly exhale with a low growl, like a wolf or dog that's not pleased with your presence. That visual is actually the opposite of the mind space you are trying to achieve, but the guttural sound is what you're after.
So that's a little something to start with. Stress management is about quieting the banshees. I had a friend who passed from cancer a few years ago. I'd go visit him from time to time and talk about what he was going through. I remember him telling me the middle of the night was the hardest time for him. At that point he was taking a fair amount of meds, some of which I'm sure were to help him sleep. We never talked then about what I'm talking about here because I didn't have the resources then to share. I'm not sure any of this would have worked for him anyway, he was a pretty tough nut, but to be able to pass along even a little something that might have helped would have been a nice thing to give to him.
I hope you find a little something in this to help you manage anything you may have going on.