That isn't how it works.
There's one dosage level for sleep, and one dosage level which is much higher and used for health.
Been using melatonin for decades to counteract caffiene late at night. Works fine for that. No issue. The correct way to do it is to take the 1mg pills and then go right to bed.
Don't take it and go shower then do other stuff. Take it, shut your eyes and do that for 3-4 days in a row. If that doesn't work, then repeat and up it to 2mg, 3mg, 4mg until you find your dose.