New to all this. Any advice welcome.

I am Mum to a lovely 13 year old son who is struggling with everything . He has been unofficially diagnosed with Asperger's and while coming to terms with this has had to cope with the death of his Grandad and his Grandma's dog. Grandma was supposed to be moving to live near to us, but that has fallen through. He has now developed all sorts of seizures and is struggling to stay in school due to anxiety. He has been diagnosed with Vitamin D deficiency is waiting for an EEG and MRI scan and his initial assessment at a wellbeing clinic. He is having counselling at school. If anyone has any advice for helping with anxiety please let me know. Is it common for a diagnosis itself to bring on more symptoms? Feeling exhausted and at a loss as to how to help him.