You should show your partitions and where they are mounted, then we don’t have to guess. As it is now, we can give only generic answers.
One possible way is to change the value from 5% to a lower value => change reserved blocks
You could mount a NTFS or FAT partition into your system, but you should not use it as $HOME. FAT is old and has some restrictions. NTFS has a lot of features, which you cannot use on Linux. In both cases, the permissions are only emulated and are slower on Linux.
The easiest solution: use a USB drive or external disk.