So in the software section i have a lot of packages to upgrade, and i have around 3MB free storage, but once i start upgrading the packages one by one i start losing my free storage to 10KB. is there a way to upgrade the packages without losing my free space.
Upgrading packages (via the CLI opkg upgrade command or the LuCI Upgrade... button) can result in major problems. It is generally highly discouraged, unless you know what you are doing or if there is specific instruction to do so.
In addition, the opkg upgrade process will consume flash storage space. Since it does not (and cannot) overwrite the original (stored in ROM), it must store the upgraded packages in the r/w overlay.