Suggest Remedy For Severe Insomnia And Depression

Hi doctor I am a severe insomniac. I often can t sleep for 24hrs or more.I also have anxiety disorder, PTSD and depression so I am in therapy and have taken all kinds of stimulates to help me sleep but none really seem to work. I have been really down lately. I am worried that the depression is coming back. Is there anything I can do to help myself?