Even though I'm not "older," only being 22 in 2 weeks, if it's something you're concerned about, then you should go see a doctor. The fact that you get pain in your neck, while also feeling pressure in your head, should be more than enough reason to see the doctor. Yes the concentrating part is also a concern, but if and I mean IF it's something like ADHD or some sort of Autism, I would be more concerned about a physical problem such as the neck pain and head pressure, over a mental problem. We can't really tell you if'll pass because I don't think anyone here is a doctor and I don't know if anyone will really get an idea of what it is, without having to guess and either give you hope/false hope or stress you out thinking you got some new disease that is slowly killing you.

If you didn't mention your neck hurting, I would have thought you were tuning people out or some people just irritate you where you feel pressure in your head because you want them to shut the hell up. I tune people out all the time and even go as far to ignore and not really grasp what a person is telling me if I'm in a shit mood because I don't care what they're saying. However the pressure I feel in my head is from hangovers unless a person is really stressing me out and I give my own head pressure inside from hitting an anger point.

im not older however i had that exact thing, not being able to concentrate or multitask. last about a week for me. just tired i think

Sounds like a thyroid problem. Get it checked out immediately because I know a girl who's suffered from this and getting it checked saved her life.

This may sound stupid to some, although, if your a heavy cannabis user, this will also be a massively contributing factor to not being able to concentrate and even when your not high!

If your anything like me, I layed off for a few weeks and I'm slowly coming back around to being myself, wanting to play a bit of sport and enjoying actually going out and talking to people. As opposed to being on cloud 14 half the time wondering what way and why the the world is spinning around me.

Edit: I in recent times have had the thyroid glands in my neck, just under my ear on one side swell to the size of a mini golf ball! They're not painful although small bursts of pain in the area just under my ear was something that I noticed.

Again, when I stopped the heavy smoking of weed this seemed to all calm down.

If your not into that, I would definitely say look into going to a doctor..

I would go to a doctor and get it checked out asap just to be on the safe side

Thank you for all the advice everyone appreciate it!
Im going to get an appointment at my local doctors and get checked to be safe.

Thanks again