My best sleep hygiene is to bathe, put on cozy pajamas, do a short meditation, then listen to an audiobook on a timer to go to sleep. The only ones I follow regularly are the cozy pajamas and audiobook. The audiobook helps so much I fall asleep very quickly, and if I wake, I listen again. I'm sorry you are having so much trouble, but I think this is what the illness is. It gets out of control and you reel it back in. Because you have the tools, you don't completely fall apart anymore. I'm using you in the general sense. I also do this.
You don't have to get down on yourself for this happening, I truly think it's just how the illness works. We are managing it by being alert to when it gets worse, and reeling it back in. It isn't anything I would have chosen, and between having cancer and having PTSD, I would choose the cancer over PTSD every day of the week. Not that I would choose either, but as an example.