How to backup my iPhone without access to Internet, PC or a Mac? I have unlimited data available on my phone, but my plan does not let me create 
a mobile hotspot. So I can’t even share my own data. I am also in a place where I do not have access to Internet or a computer and my iPhone needs to be backed up.

Is there any way I could possibly get this done?
You can enable iCloud backup in your settings. You will not need to create a hotspot, only use your data to upload the backup to your iCloud account.