Although in most probability it should be concussion
only,but it can not be taken lightly and you must immediately rush to ER to get a MRI
skull done to look for any intracranial bleeding.
Treatment for concussion lies in ice pack locally,adequate rest and taking pain killers.
Sometimes the recovery of concussion may take long and it happens specially in those people who are old or if you had a past concussion also,like you had in past.
I hope it helps.