Welcome to HCM!
I have read your question and from that it is apparent that you are having headaches
from past four months, along with difficulty I retaining information due to which your grades are getting affected. And you are worried about all this.
Had I been at your place I would definitely see a doctor for this, espically when it looks like you have been a good student prior to this and are really concerned about studies.
Getting an MRI
brain will rule out anything organic. if it comes normal, then it will be wise to see a psychiatrist
and discuss your problem in detail. one mayhave as similar presentation in cases of stress/depression
--- of lack of concentration and headaches etc. which are completely treatable.
So, first it will be good to rule out organicity.
for now , if you have headache, aceclofenac
sodium may help in it.
hope you get well soon!
Feel free to ask more queries
Dr. Manisha Gopal