I hope we did not just talk but understood each other What value are you dividing by 1024?
...snip... #Get Swap size from /proc/swaps swapsize=$(awk '{if ($1=="'"/dev/$disk"'") print $3}' /proc/swaps) #Divide by 1024 to get swap size in megabytes swapsizembytes=$(($swapsize/1024)) ...snip...
Not so unusual. I get my swap space (now 2x 1,5GB filled up in one day with heavy browsing, mailing and a few more phone calls). So reaching 2GB after 1 day is possible.
Above will work. There will be no need for another solution. TB=TeraByte, i.e. 1000GB I do not think we will reach that amount of used swap. Even after a year uptime