Not Medical Advice:

Amigo, glad to hear that Magnesium supplements are helping out! TBH, it’s hard to know how/why it’s working for you specifically. A few folks have told me it really improves their sleep quality, which can definitely improve energy levels and mood.

As long as your kidney function is normal (extra Magnesium is excreted by the kidneys), the dose you mentioned in your note should be safe. People with impaired kidney function need to be careful with the dosing. I’ve seen one case of overdose (with nausea, cramping and abnormal heart rhythms) in a patient on dialysis. Otherwise, there’s not much downside as long as you stick to your current dose. 

P.S. It’s probably not worth checking Magnesium levels in the blood — The blood levels don’t correlate well with total-body Magnesium, which is stored mostly in bones.

https://www.mountsinai.org/health-library/supplement/magnesium