Dreams involving falling or being dropped can often symbolize feelings of helplessness or loss of control in your waking life. The fact that your friend grabbed you by the neck may suggest feelings of betrayal or a fear of being overpowered by someone you trust.
Being in a classroom setting could indicate that this situation relates to your learning environment or personal development. It might be worth reflecting on your current relationships and any underlying tensions you may have with friends or peers.
Consider asking yourself these questions: Are there any conflicts or feelings of vulnerability in your friendships? Do you feel pressure in your academic or social life? Exploring these themes may help you gain clarity on the emotions represented in your dream.