Hi - and welcome ~
To be honest, every AN patient handles the diagnosis and treatment decision a bit differently. Naturally, many are upset, even panicky for a time but eventually that passes as you gain more information about what you have, how to deal with it and what to expect after treatment. Some AN patients are very methodical and gather information, categorize it, ask questions (both to doctors and here on these forums) then make a deliberate, informed decision. Some of us (Jim raises his hand) aren't diagnosed until their AN is very large and impacting their brain stem, making surgery the only option - and the sooner the better. Although some take their AN diagnosis calmly, relieved that it isn't cancer, none of us are sanguine with this diagnosis. One has to studiously avoid allowing the 'what if's' to overcome us and make us so worried that we'll experience a bad outcome following surgery or radiation that we can't make a decision. The cold hard fact is that, like many things in life, there are no guarantees with AN treatments, be it surgery or radiation, no matter the doctor, the method of treatment (Retrosigmoid, Translab or Middle Fossa surgery) or radiation (CyberKnife or GammaKnife) - or even a combination. I underwent debulking surgery ('Retro'), then (90 days later) FSR (26 sessions) and had a very good outcome with basically no complications, not even a headache. Others here enjoyed similar outcomes while some did have some issues to deal with and in relatively rare cases, some AN post-treatment patients struggle with seemingly intractable problems. However, even when post-treatment problems arise, they are almost always temporary.
We usually advise 'newbies' (newly diagnosed AN patients)to step back, take some deep breaths and don't try to learn everything all at once because, as you note, it can be overwhelming. We even suggest taking some 'time off' from perusing these forums so as not to overload yourself with Too Much Information. However, we stand ready to inform, advise and support you as you work through this phase of your AN journey. I'm sure others will be along to offer more suggestions and to welcome you here.
Jim