Anxious child

This will be long so please bear with me! My 11 year old girl is being referred to the appropriate place to potentially diagnose ADHD. For a while she has had a lot of anxiety around me (her mum) ie if I go away for a few days and don't answer my phone she gets herself so so worried. If I have a Drs appointment she gets herself so wound up. She's worried of me dying. My mum, her nana, has chronic fatigue and other health problems and is now bed bound and unfortunately will get worse. My daughter recently told me for a while she's been experiencing episodes where she HAS to do certain things her brain tells her to do or her nana will die. She's also said recently about seeing a black man figure at night. She says her brain never switches off. I'm going to take her to the Drs tomorrow but just wanted to see if anyone has advice as I'm genuinely worried for her to feel like this at such a young age.