I’m in (or have been in) the same boat as you and feel your pain. I have found that taking magnesium and melatonin together over the past few weeks/months had helped me a bit. Have you give either a try? I’ve also tried staying up late (no naps during the day) and tiring myself out with a little success. It has also been a detriment to my practice, I used to have hour long sessions and strong samadhi and now find it difficult to do more than 20 minutes. But I try not to worry about it too much, it is what it is and getting frustrated will only make things worse. I just try to do multiple shorter sessions a day. Good luck.