Ouch - that hurts. Maybe because the people your friend has been hanging out with don't know as much about her as you do, she might find some relief from her issues when she is with them - sort of like pretending things are OK for a while. It may feel like it is about you but it is really about her. She may just be sick and tired of being sick and tired.

You can bet that when she has a problem, you will be the first one she calls. Stay in 'gentle' touch with her - she needs you and you need her.