I found out I had a 7mm aneurysm 3 years ago took about 3 months for me to get fully diagnosed before Stanford University recommended that I have surgery within the next week. It's super frightening at first but you're going to be fine. They'll do additional tests to map outthe size and location, create a 3d model of it and what the best treatment option is. I will say I had to go to 2 neurologists before I found one that recommended me to see a surgeon they all have different thresholds. I was lucky, my surgeon Dr Steinberg at Stanford. He's one of the best in the field the surgery wasn't great but I was mountain biking 2 months later and haven't had a single symptom since and it was a full craniotomy. Of course I'm having surgery at the Mayo Clinic in July for two heart aneurysms but that's another story. You will be fine, ask questions, read real journal articles not the BS on the web.