Thanks for your question. I'm happy to help you today.
I can understand what a frustrating problem this is, especially since it sounds like you've never really gotten a truly good night of sleep in your entire life. You say that you have tried everything, but since I am not sure what "everything" encompasses for you I would make a suggestion that you consult a sleep disorders clinic (and you may very well have tried this already). You might also want to read this information regarding the many different types of sleep disorders to see if you think any of it pertains to your specific situation:
You can search this website to find a sleep disorders clinic near you:
However, due to the information you provided regarding what happened to you when you were three, I'd say it sounds like you might be suffering from PTSD (post-traumatic stress
disorder), although we cannot provide a specific diagnosis here and this is just for informational purposes only. You might find this information from the Mayo Clinic helpful, especially if this is a diagnosis that no one has considered before:
In order to confirm any diagnosis, you'd need to see a psychiatrist for an evaluation. They can conduct a thorough investigation as well as recommend a course of treatment (see the Mayo Clinic article on PTSD side tab under treatments for more information).
If you don't already have a psychiatrist, you can ask your GP for a referral or check this website:
Regardless of the diagnosis, there are medications and treatments that can help you.
If you'd like to discuss this more or need more information, please let me know. I hope this information has been helpful to you. Best of luck.