Did I commit a sin by supplicating against a group of circumambulators who caused me harm and pushed me, and what is the ruling on forming enclosed groups that harm circumambulators?

If harming people is unintentional, then it is not permissible to supplicate against them. Patience and forgiveness are more befitting in such situations, and the default is to assume good intentions on the part of Muslims. As for harming Muslims, it is forbidden, especially during the circumambulation (Tawaf), due to the حديث (Prophetic narration) prohibiting jostling and because refraining from harm is obligatory.