I don't know what your host provides - do you have Cpanel? I have seen some Indian websites that have something called Free Installer, which seems to work somewhat like Softaculous.
All Abantecart software is open source (free) ask your host about the installer - they have more knowledge of what is available on your account.
The rest of us just have to guess based on generalities.
Ask your host if there is a backup that is done automatically - some sites have this. If so they can perhaps assist you in returning to your previous version.