Advice

My son is 18years and was diagnosed with ASD when he was around 13 years old. Gradually over time his behaviour has become more and more challenging. His anxiety has become worse and he refuses to go to college, his grades have dropped. He now doesn't want to go to college because he says the TA's in each class make him feel stupid. I'm getting zero support from college and they never call me back. I've been told by my son that he has failed an exam, he cam resit but he looks deflated and says 'whats the point'. I've been to the gp 3 times and they send him away with an online Cbt To complete. I've tried groups but he hates being around lots of people and he won't acknowledge his Asd diagnosis at all. I can see him withdrawe with every passing day and no one is helping me to help him. Any suggestions