Is it an allergy? I am allergic to Sabril and the same things happened to me. Have you rang or seen your neurologist? I mean, to me that's what it sounds like...

I tale briviact and haven’t had any symptoms at all.

Yes, I take Briviact. And it does have the adverse side effect of anxiety & aggression. Plus with him having Austim puts an increase on the adverse side effects due to how much the sensory skills affect his personality. My daughter who's now 16 has HFA, I know where your coming from. Do you ever give him vitamins like C, D, Fish Oil, & Magnesium? All are very beneficial for nerves/brain. Even have him soak in the tub at night for 20 mins in Epson Salt (1 cup) with Coconut oil (3 tbsp). Epson Salt has magnesium & sulfate in it. Both will relax and tone nerves while which helps with falling asleep at night. Plus the magnesium and sulfate stays in the system a good 18 hrs. It did wonders for my daughter when puberty kicked in. Eased cramps, mood, focus, etc. I hope this helps.