She is fine... .moving on with new boyfriend.
She is not "fine" sweetie - she really isn't.
She has taken all the old baggage with her into a new relationship - she hasn't done any spring cleaning and got rid of useless or broken items - because she believes that these items have and will serve her well.
If she is BP then she may have found something fill that void for now - but her new partner (being a mere human being) will let her down - just like you did and the next one will and on and on - unless she gets help.
Don't go hanging around on the off chance that she may see the light and come back to you. Do you really want to be "second choice" in someone's life? I know I don't - I am "first" or not at all now.
You acted on your gut instinct - it has served you well. She cannot be alone - that in itself raises questions about her stability. She hasn't had time to catch her breath before she replaced the man in her life with another one - blink and you might miss it.
I understand why you might feel jealous. But logically why are you jealous that another person has taken it upon himself to try and cure her of this disorder - do you think he will succeed - is he a fully trained and experienced therapist - that takes patients into his home and has a relationship with them in the name of "therapy". If this is the case - he goes beyond the call of duty.
Whatever she has been diagnosed with is now her problem to deal with. I know it's really difficult to stop putting all the focus onto them.
Take it easy, do stuff just for you - it will get better if you work at it.
Minks