I have to think that "insomnia" is a condition and not an Illness/Disease.
I have a pretty bad problem with insomnia, but I suffer from several medical problems that are probably the root cause. Then there are the medications I take for my medical problems, many of which list "insomnia" as a possible side effect. The stupid thing is, a medication can list both insomnia and drowsiness/sleepiness as possible side effects. To me, that's an oxymoron, but that's the nature of the human condition, everybody's physiology works differently.
I take 200mg of Trazadone to help me go to sleep. Not working so well. I usually get 3 to 4 hours of sleep most nights, if I'm lucky. When I do sleep, a bulldozer could knock down my walls and I'd never wake up. My Dad can come over to my apartment to drop something off, sit down, watch TV, play with my cats, pretty much anything, and I'm none the wiser. Usually the only way I can tell that he's been here is that the mail is on the table or a newly filled prescription has been delivered. That's pretty creepy. I am able to answer the phone in my sleep and carry on a conversation, but have no recollection of it when I wake up. That's scary.
I have very vivid nightmares, and if the weather changes overnight, I'll wake up with a migraine. Even worse, I have a really bad back, and when I wake up, I can barely walk.
So many days I wish I could just lay in bed and sleep, but I just can't.
I hope you can find the root of your problem and catch some zzzzzzzz....