So the things that help me the best. Making sure I do my self-care. For me that looks like meditation, exercise, seeing a therapist, and going to mental health support groups (NAMI it's an excellent resource for this).
Here's a meditation that will help you to be more aware of your thoughts and some techniques to help you ground.
This is more of a practice and less of something to do when you're having a ton of racing thoughts.
And this is a body scan, you can use this to help your body relax and your mind to be aware of your body instead of your thoughts. It would be helpful to try to fall asleep to it. And if you can't fall asleep at least to relax and get more rest.