Melatonin doesn't seem to be ideal for me. I'm taking 3mg and while it does knock me out fairly quickly, I'll wake up only a few hours later and find it almost

Melatonin doesn't seem to be ideal for me. I'm taking 3mg and while it does knock me out fairly quickly, I'll wake up only a few hours later and find it almost impossible to get back to sleep again. I'm usually even more tired than I would have been without it. I've cut caffeine completely out of my diet and I'm finding it very difficult to concentrate, theres a fog in my brain which only occasionally lifts (and on those days I get loads done)