Have you tried the simpler things yet? Example, removing all artificial light and/or sound source, meditation, do not eat 3 hours before bedtime, do not perform strenuous activities 3 hours before bedtime, sleeping in your own bed, etc?

What do you eat for your meals? What is your physical activity level? Do you work shift hours?

I'm asking because if you don't make the necessary adjustments to your lifestyle, the magnesium might not help.