When I back sweeten with honey, I get it racked off the sediment once I'm happy that the ferment has finished. Then I hit it with sulphite and sorbate too stabilise it, the I mix the sweetening honey with water 50/50 then once I've taken a hydrometer reading, I add a little of the "syrup" (about 100 mls) and then stir it in gently, to make sure its properly mixed in. Then measure gravity again. I'd be aiming for between 1.010 and 1.020 as that's the area I like my meads. If you did that but have a little taste you'll find the point where you like the level of sweetness.
I do the sweetening at this point, because honey can cause a haze (protein I believe) and its a PITA to clear it only to get a haze and have to clear it a second time.
Then I just let it clear over time while its ageing......
Just for a 4 gallon batch hoe much sulfite and sorbate should I add.