I believe that the mind can moving too fast, i.e. it's too aroused, and this can prevent sleep.

For dealing with anxiety / depression, I've found it helps to simply notice and try to accept the emotion while you're feeling it, and remember that it will pass, even if it takes a while. Sometimes I can go most of a day feeling depressed, and then suddenly in the evening I feel better. I had panic attacks for a number of days but those seem to have mostly stopped - the thing I found helpful was again to simply accept what was going on, recognize that it's a panic attack (which feels extremely scary but is not dangerous) and have faith that it will pass.
I've also been trying a bit of meditation and light exercise. I think it's improving things a bit - make sure to listen to your body and back off if / when symptoms increase.
The body needs time to heal, and we need to be patient and stay hopeful. I hope that helps - feel free to message me anytime.