You should definitely discuss this with a medical professional.
I know your next appointment isn't for 3 weeks, but if you phone up and explain what has been happening, they might bring your appointment forward.
As for what this could be, well, it could be any of the things people have already suggested here - schizophrenia, some kind of panic disorder, sleep disorder, medication reaction, it could even be extreme stress.
I don't know if it is something that could be directly attributed to AS. Although, interestingly, some people with Tourette's Syndrome experience 'intrusive thoughts' and as TS in a neuro-developmental disorder (like AS) perhaps there could be some connection - but I really can't be sure of this - you really need to consult a professional.
Feeling hyper and having hallucinations could also be a symptom of bi-polar disorder, which could also be responsible for the sleep problems you have.
But you MUST see a doctor as soon as you can.