It seems from the history that you had a injury to the head about 2 days back. Since you are not having vomiting, dizziness
, pupils of same size..., no need to worry as you are not having any symptom suggestive of head injury
The tenderness is probably because of local injury to the site and hematoma. This will resolve in 3-4 weeks and you can take analgesic
drugs for pain relief.