Help my lenovo adroid got it's operating system damaged i think?

Because too much malware i decided to factory reset but them malware is still there and i can't connect google play. It says to fix google play i need to delete host file but it's for rooted phones only so i keep hitting factory reset maybe i get lucky then suddenly there's a pop up to upgrade my lenovo to latest version so i downloaded the 21mb update and then updated failed. Operating system died. So now i'm trying to download a ROM for lenovo tab 2 a7-30hc but what i saw is 16gb! Wow! My SD card is only 8gb it doesn't make any sense

The steps i took to try revive it is update from sd card: them folders are empty. Wipe data/factory reset, failed restore user data. It says no sd card wtf! I tried system partition check failed. System have been rooted. Eh? I didn't remember rooting my phone and i don't have the knowledge to do that