If the anxiety is akasthesia from the risperidone (can not sit still, feeling like you want to jump out of your skin, need to move & pace) the anti-cholinergic effect of diphenahydramine (benedryl) offsets akasthesia. benedryl might also help with getting sleep. Did you take the risperidone because your trip was getting bad? Are things mostly better now? No need to do more than 50mg of benedryl to ofset akasthesia and get some sedation if the anxiety is akasthesia.