I can emphasize with your insomnia - as a fellow sufferer. I have had this my entire adult life as well - usually from being on steroids to control my asthma. High or low dose affect me this way. I drink NO caffeine or sugary drinks, and stay away from chocolate/other products which have caffeine. Sometimes I will sleep for 15 minutes and then am up for the rest of the night.
Things that have helped - sometimes - are calcium at night -- no more than 600mg as more than that the body will not absorb at night. Magnesium Glycinate (I get this from Amazon) can have other vitamins. Take in the morning. Some take it at night - which worsens the insomnia. I cannot take Melatonin as I get hyper and more awake! Tryptophan (ingredient in turkey) can be helpful. Benadryl can be taken - though if it does help, after about 5 days you get very bad nightmares. Try a cool room with blackout shades or even wearing a sleep mask.

It is possible to have some sleep apnea - even though you don't sleep. It is hard to get checked for that - even with a home test - since you need to sleep for at least 4 hours in a row. Can you sleep sitting in a chair or with the head of your bed more elevated (use blankets or pillows under the top of your mattress, so your neck won't hurt.

The last resort may be some self-hypnosis and white noise.
I hope you get some much needed rest/sleep. It is difficult to function without rest - something the body needs to repair itself. Good luck.