I've somehow managed to convince myself that I have a brain tumor.

I've also developed a bit of a stutter.

Hello. I was in the same boat and I still kinda am. I'm sure you're tired of hearing this but you really have to stop googling. if you can't stop, switch websites. I used to use webmd and they told me I'm dying so many times..now I get on here or other anxiety sites and people have all my symptoms. I had the head pressure and ear pressure and I kept telling myself everyday I had a brain tumor and then I slowly developed every single symptom except seizures..once I stopped thinking about it, the symptoms were gone. if you're that scared you might need to just go to the doctor just to get the okay but I'm sure you're fine. praying helps me a lot and I'll be praying for you ?? I hope you recover soon 

Those are the same symptoms I’ve been experiencing.... have u ever heard of ice pick headaches? They are like sharp pains in your head that last all of 3 seconds. I thought I was having a brain aneurysm.

I know how you are feeling, I go through the same thing, anxiety is cruel, I often convince myself that I have a heart problem or even a lung problem but I have been to my doctor and found nothing, googling symptoms makes it worse, after running on to this site and seeing others who are going through the same things I am is giving me some relief that it is all in my head

Yeah, I have those symptoms.  I actually become more sensitive to everything, light, touch, sound, smells.  Hearing may sound very loud and magnified.  Smells can become unbearable.  Adrenaline makes you look out for danger and ready to react.  It is so you can detect the first sign of a threat. A very basic animal response hardwire in the brain in case of emergency.  I was diagnosed with somatic symptom disorder.  Other than that they found nothing wrong.  I insisted on a brain MRI.  It is kind of like fibromyalgia that is also related to overactive nerves?  Do the experts even know for sure?  

Are you going through a stressful period in your life at this time ?

The problem is if you have brainwashed yourself with Google, you will worry more and more on what you have seen on the web. A GP is the only way you will get some relief from your fears.

Look at it the way I do, I do not know how old you are, I also need to know if you have been diagnosed   earlier with Anxiety.

However initially I would suggest an NSIDs medication to get rid of your headache, take a course of  a Brufen type medication from the chemist, they will advise on the best one for you. After about a week if the headache is still there it may be Stress, talk to your family Doctor.

If you could be seen by a health professional I would suggest you talk to them and they will check you out.

BOB