Right, right. Now keep doing that. And after the fight, work out the following: all arrows which hit are destroyed. Half of the arrows which missed are destroyed under normal circumstances. Double check with your DM whether you are in abnormal circumstances, like shooting at a sea serpent, that would cause your arrows to become lost at a higher rate. The remaining arrows may be salvaged. Replace them in your quiver. Then go to your larger backup storage of arrows and top off your quiver. Mark down how much your backup storage has diminished. You DO have one, right? You didn't go adventuring into the Underdark with just 60 arrows, right? Of course you didn't. So mark off how many of the nearly 2000 arrows in your backup have been used.
That's what you have to do. Its not mentally challenging, its just time consuming, and it doesn't do anything important! It just determines whether you spend 10 gp or 12 gp the next time you get to town! You aren't going to run out because you have a bag of holding stuffed with arrows anyways. Of course you have this, because other than a bag of holding, the next best item in the core rules holds 60 arrows. And that's nonviable for a lengthy trip because even at level 6 you'll use that up in 20 rounds of full rapid shooting fire.
Honestly, at higher levels I'd be happy to just pay 100 gp every time I got to town in order to avoid having to mess with the whole matter.