Why do I get bumps w/ my head ache?

about 3 years ago i had bumped the back of my head REALLY hard, but didnt make much out of it... ever since then i had gotten really bandmigranes that had also mad me vomit at times. i then went to an MRI about 2 yrs ago and they said everything was normal.
since then my headache arent as bad but i just have very tender spot with many buts on my head that do change position at time. i know when im getting a head ache because a bump shows up, or vice verse.
the bumps themselves become very tender and can sometimes cause my neck to feel week.
What can this be?

[Dr Santos]

Hi,
How are you? Are there other symptoms present? It is good that the MRI results were fine. After trauma to the head, headaches are usually observed months to years after the. Can you elaborate on the bumps ? I recommend that you have this checked by your doctor for direct clinical examination. Additional diagnostic tests such as MRA  may be done for proper evaluation. Take care and do keep us posted.