Help me pleeezzz 💕💕

I am 20F
So I live in my college hostel in bangalore and been there since a year. I have been facing extreme hairfall due to hard water itself.
I would keep it short.. I can’t get filter water once a week (should I buy bisleri bottle or water can every week) or should I purchase water softener liquid.
Cuz there is a water shortage in hostel .. I mean there are many people in hostel there is no water in filter which is filled twice a day … so it won’t be fair to take that water to wash my hair.. we sometimes wait half half days to get our bottles filled.
Those shower filters won’t fit in hostel taps cuz the shape is a bit weird big.
So what do I do?

Help me out .. thank u so muchh ❤️‍🩹❤️‍🩹