If you are a beginner, maybe try backsweetening in a future batch, after you have learned how to use you hydrometer. You can always sweeten in the glass. But you may have made something already good to you taste preference. How long it takes to mellow and age to tastiness (instead of paint stripper) depends on your recipe. Taste at bottling so you have something to compare it to.
Did you make a JOAM? Let age 3-4 months then taste every month. It will change a lot
Did you make a BOMM? Start taste testing after a month
Other recipes will probably take 4-6 months. Some recipes are designed to take years to mellow. But then you get an extra special product. I don’t have that much patience. I once had to wait 5 years for a coffee mead to go from ashtray to drinkable.
But taste testing is part of the learning process
Keep notes on every batch so you learn and remember what you did. And can replicate it.
And if you get anxious…rush out to you nearest alcohol store, buy the strangest can of beer you can find. Rush home and bring it very close to your fermenter. Crack it open, pour into a glass, sit down and enjoy. If it’s good, it will teach your brew what to do. If it’s bad, we’ll, your batch must be better, so be patient and wait (sneaking tastes is ok too)