OTC stuff is, for the most part, useless. That includes melatonin, diphenhydramine, doxylamine, valerian, etc. Melatonin is especially bad, even more so when you consider how terribly its manufacture is controlled in this country.

I've seen data on that purple-top melatonin that would make your head spin.
Follow proper sleep hygiene and see a sleep specialist about insomnia-focused cognitive-behavioral therapy. If the lorazepam and zolpidem haven't worked, it's time to explore new options. There are other pharmaceutical options but you're not quite to the point of needing those, yet.

Side effects get very nasty.
edit: thought the picture was the TS posting.

Anyway, I doubt melatonin works for you regardless, what you're describing is a little different. You're welcome to try it, but don't say I didn't warn you. There are plenty of better options out there.