You should never be rushed into an immediate decision like this within 24-hours especially since acoustic neuromas are usually very slow growing and pose no immediate threat (with your small size AN).
The reasons most people "watch & wait" and forgo treatment are because there are a lot of things that can cause mild-to-permanent complications for your future life. For example, just look at all the sub-categories on this website (hearing loss, headaches, face paralysis, eye complications, balance problems, cognitive issues, tinnitus, fatigue, loss of energy, nausea, etc.)
You have to take time to research, weigh the pros and cons of each option, and then make your decision to either go with treatment or "watch and wait" with lifetime MRI's.
You're the one who is going to have to live the rest of your life with the outcome.