Hemorrhoids do not develop from fall so this thing is sure. I would recommend you to show it to a orthopaedic surgeon
and we will be sure about that nodule. Do you have constipation
or bleeding per rectum in past. If not i believe it is organised hematoma
or a malunited coccyx fracture
. til that time you can do hot water fomentation by sitting in a tub filled with gentle warm water.