Swelling is suggestive of hematoma
formation(Collection of blood) and cranial bone fracture
Headache also indicates that there is some pressure effect in that area.
This may lead to long term complications like cerebral atrophy
You're also prone for infection due to defect in the cranium.
CT or MRI of the cranium and brain will help in assessing the extent of the damage.
Do consult your doctor.