Hello Cherie,
I think I can tell what has happened. Normally, hair is strong enough to be held in a loose ponytail, however when hair has been over-processed it is weakened and is much more susceptible to breakage. If you have had your hair bleached then there may have been some overlapping onto the pre-lightened part of the hair - this happens sometimes when the bleach expands as it’s processing - which also makes the hair brittle. If the ponytail then pulled the hair at the crown it could have added to the stress on the hair.
The best solution now is to continue to treat the hair with a protein-enriched shampoo, conditioner and treatment, like the one specially formulated by Bumble&bumble. It's also important to research the salons you go to for colour or bleaching services to ensure you visit one with a good reputation for this kind of service.
Thanks,
Linzi King, Simon Webster Hair, BrightonÂ