Hi Rachelle
Thanks for sharing your story about Bb.
I have had cockatiels myself and I didn't know that about them not showing they are sick until it's too late. If it's any consolation I've always rushed mine to the vets and they've had injections and things but it's never worked and I've then felt guilty for unsettling them with a dash to the vets when it didn't help anyway.
I hope the site and sharing your story has helped a bit at least.