On a loosely-related note, if your work involves computers, allow me to recommend this awesome free clipboard program.
It turns your Windows clipboard into a history. Ctrl+v still pastes the last thing, but when you hit the hotkey to trigger Ditto, (I bound it it Ctrl+`) then you can paste any of the PREVIOUS things you had.
It's great. Doesn't take anything away, and adds a great little power.
Be aware that melatonin is completely unregulated by the FDA or whatever the equivalent in your country. That means that formulation and dosage varies by brand / lab. The little science available suggest that 350 mcg (I think, can't remember the exact number) is the appropriate dosage. If you go to the store you'll see presentations vastly exceeding this dosage, going up to 10, 20 mg. If you are interested in starting out at the alleged right dosage, I suggest Sundown Naturals, you can find it on Amazon.
https://www.amazon.com/Sundown-Naturals-Melatonin-300-Tablets/dp/B000GG2I9O