Hi Eeeber35,
You will find many here who deal with headaches and pressure both pre and post treatment. For some it's random and comes and goes, others deal with it more ongoing. There are also many folks, who have no issue at all with headaches.
I was also diagnosed with a 1.8cm AN on my right side. Around the time of my diagnosis and during the first year after (but pre treatment) I had continual headaches up the back of my head that would occur only when I was lying down and they would wake me when sleeping. If I sat up for a while the headaches would go away. I had one Otolaryngologist tell me they had nothing to do with my AN and I had a Neurosurgeon tell me anything was possible. I can tell you, that about 2 months prior to my Gamma and during the last 6 months post Gamma, I no longer have those types of headaches.
As for pressure or pain, I've had some pressure but it is recent and most likely due to some post Gamma swelling. I have never had any pain.
Take care,
Cathie