Sorry to hear that you’re struggling.
I find yoga helpful, not necessarily the physical postures/stretching but the other things that come with it:
Breathing techniques, for example establishing a slow steady breath and then trying to extend your out breath slightly longer than the in. So you might count 4 on the in breath and 6 on the out. I find it works better to try to settle in to a comfortable pace for you, and then fit the count to that. If you find it feels uncomfortable or panicky at any point just stop counting and concentrate on slow and steady at your own pace.
Grounding using your senses: for example close your eyes (if you’re comfortable and safe to do so), and listen to everything you can hear. What is closer, what is further away? What can you feel against your skin? Feel the weight of your body on the floor/chair/bed. What is the temperature like in the room? Is there a breeze?
For getting to sleep, counting down from a big number (like, start at 35,729 or some other random big number) - and I say it out in full in my head - stops my brain from doing anything else like worrying. If that’s not distracting enough, try counting down in 3s (so the next one would be thirty five thousand seven hundred and twenty six…)
As well as real life classes I use the Down Dog yoga app (paid for - started during lockdown when there were no classes!), but friends swear by Adrienne on youtube for free.
Does your employer have an Employee Assistance Programme? Mine offers free counselling, CBT, a quite good app with stuff like a mood tracker and live chat with counsellors, and we get a free Headspace subscription too, so it’s worth exploring if there might be things you can access. Good luck!