This sucks, sorry you've lost hair!
this makes me paranoid. Just started co-washing 19 days ago and i have been measuring my ponytail diameter and its stayed consistant - but the amount of shedding in the shower is ridiculous. Even when i only have a day between detangles. It's just hard for me to think of any logical reason why omitting shampoo or moisturizing your hair cuticle would cause hair loss. I'll keep measuring my ponytail weekly.