I will quote from a very good reference here:
"Subarachnoid bleeding may also occur with a head injury of any type. Worsening headache and other signs of increasing intracranial pressure will gradually grow after the initial event"
In fact, any concussion can be a sign of a serious problem, and the apparent strength of the blow does not exactly correlate with what happens to the brain.
However, I will also note that you stated that you hit your head "quite badly". Not a mild blow.
Effects of a blow to the head, and even post concussion syndrome, can show up well after the initial blow.
Alcohol has a reversible inhibition effect on platelets, much like aspirin. The fact that your symptoms got worse after heavy drinking is not a safety factor, but an added risk factor.
You will at minimum need your doctor to follow you, and standard of care dictates that a doctor see you now, so that there is a baseline recorded to compare to later. This is how we do things in safe and proper medicine.
We do not diagnose over the internet without exam. I would not be ethical if I did not tell you to see someone now.
I am at your service for follow up any time. I am here daily and you can easily find me by request.
OK, so that is an initial answer….
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