Sudden headache, feels like my head is being squeezed

[TheUnnamedNewbie]

Hi,

The last few days I've had a headache I've never had (or at least cannot remember) before. On both occasions, they have been "triggerd" while I was showering and looking up (when rinsing the soap out of my hair or mastrubating). The seem to come out of nowhere, and in a matter of seconds I go from feeling fine to needing to grab something to hold myself up because the pain is so intense. The pain originates on the back of my head, around the area where my skull seems to end. The first time it happened, it felt like something was squeezing my head.
Once this has occurred, a few dozen seconds later the pain fades (from I can barely stand up to it really hurts and it prevents me from concentrating on anything). and moves to become a more spread out pain, with similar squeezing sensations above my eyes and ears. It will then slowly go away over the course of a few hours, sometimes accompanied with a brief (seconds to half a minute) pounding.pulsating sensation similar to you feel when you have sprained your ankle and feel it pulsating (I don't know how else to describe this).
I felt dizzy in both cases, and the first time I felt like I was blacking out but never completely did.
When I felt it "starting" the second time, I thought it might be a cramp so tried moving my head gently around since I know that helps when I get cramps in other muscles sometimes. While it did seem to take longer to get to full "pain", it did not work and the pain still kept "growing". After a while, I also get a pressure sensation on the top of my eyes.

I have been under a lot of stress the last few days, but this is far from the first time and I've never had any reaction to it like I have now.

I'm 21 years old, male. I take 90mg of Concerta (Methylphenidate) per day, and have done so for a 15 years now (building up the dosage of course, I've been on 90mg since the beginning of this year).
I'm not atheletic, but am at a healthy weight.

[selmaS]

  Hi, it doesn't appear to be a side effect of your meds....and I am sure your Dr keeps track of the levels in your system....

Do talk with your Dr and review  your families medical history to see if you could have a disk issues that tighten the flow of CSF fluid when you look up...as you bend your neck it may be making things tighter....???

Your Dr may want to do  a MRI.....let us know what you find out...Good Luck.