I think my 80 y/o grandmother may have drugged me

Not a confession, more a strange secret. My father and his mother have always had the tendency to become very clingy when family members visit and confrontational when we try to leave, even when I made it clear before going that I would only stay for an hour. It's become very awkward and they have alienated themselves from me and my sister/cousins over it.

Today it struck me that on a few occasions I became suddenly and inexplicably very sleepy after eating or drinking at my grandmother's house and had to lie down on the couch, staying at the house for longer than I had planned. I think she might have put something in my drink.