Hi, QU,
And welcome to SR!
My son is dual diagnosed with heroin addiction and bipolar disorder. I understand your anxiety and confusion. I will say, though, that it doesn't seem as if your anxiety is under control right now. Have you called your doctor? That may be a helpful suggestion.
The suggestions made by the hospital people, to do something your enjoy, is a good one. What they're trying to communicate is this: YOu cannot help anyone else if you cannot help yourself first. So, you've got to get your own anxiety in order before you can begin to help him. Alanon meetings, and working with a sponsor right now is a great idea. You may wish to talk with a counselor right now too, while your anxiety is so high.
I have no experience with lamactil. I hope it works out for him. Sometimes, it takes a while and a few different types of meds to get it under control.
Remember to take it one day at a time. My thoughts and prayers are with you.
Shalom!