HEllo-
What you are feeling the derealization is normal to with panic attacks, i experince it myself and i get very scared, i have to actually ask my husband or whom ever is around me if i am really here. I have to touch myself and sometimes i feel weird but its just that our adernal is going and nothing seems to feel,look, or seem right. But you know i have learned to float and accept this feeling, and as hard as this sounds try not to think about it, the more we think about it and put thought to it the more the feelings will last and the more intense they will be. So try to not think of it and it will go away.
I have had a reaction to a over the counter medicine actually is was Dayquil, let me tell you that through me into the worst panic attack i have ever had in my life, and i actaully thought i couldnt walk move or nothing and i just layed in bed talking to my dad telling him i was going i was leaving this world, and thats the first time i had experienced that and my told me no its just panic from the medicine with a little bit of a reaction to it.
Now when i experince i just either accept it and try to get my mind occupied with other things or i ask my husband or if no one is around i call someone cause i know for sure if i am talking to someone i am here LOL, i will even ask the other person i am talking to you right, they say yes and i say but it still feels like i am not talking. Another thing i read somewhere is to put a rubber band on your wrist and when you get this feeling snap the rubber band, and you know for sure your here LOL.
Hope this made you feel better! :)
It always helps me to know that other people are feeling the same sensations i am. )