@aethelwulfe
Been through this many times with mentally trying to deal with issues. Just went through this with loss of PTSD Service dog and spending 5 days in cardiac critical care because of ICD shocks.

What I found is that medication can really help. Just having them can provide a feeling of it is there if needed. What I try to do during periods like this is to get physically tired. You have to have the O.K. from your doctors but getting physical tired will help you sleep.

I do exercises that really help tire me out and also bring some joy to me when doing. So getting best on both ends as helps me both physically and mentally.

I do water aerobics 5 days a week. On three days do back to back classes. I also bike and walk in pool. What I found out is if I get physically tired I am able to fall asleep and not have my mind racing. I have been prescribed medications to sleep (Trazodone, and Lorazepam) but I rarely take them now as have been able to get back to my exercise routine after getting out of hospital.

Exercise brings endorphins which helps you mental well being. Of course you have to find and exercise (doctors permission) you like to do. If you are smiling during your exercise you have found it. If exercise is not for you consider a hobby that you like to do. Anything that brings a smile of enjoyment is something like medicine for the brain.