A new onset headache following a hit to the head (ie the elbowing) is concerning. The fact that you have slept 36 hours in 3 days, which is more than your normal, is concerning as well.
I would advise that you call your family physician as soon as you can as you may need a referral for a CT (cat scan) of your head.
If the pain is severe to you or you are having other symptoms such as blurred vision
, you need to go the ER immediately for evaluation.
Be well, Dr. Kimberly