If you were painting with solvent based paints, the fumes could be part of your problem. But, most room paints are latex and/or Low VOC so the inhaled fumes are minimal.

The re-injury is likely the cause of your symptoms.

Have you been icing your head and neck? It will likely help.

Your recovery should be quicker this time because you have a better understanding of how to take care of yourself. Get the good quiet rest and you should do fine.

My best to you.

Oh yeah, Don't bump your head again. I've tried this since I was 16 but have bumped my head 10 times more in 40 years. LOL