Welcome to the forum Mariska.
It seems that your main motivation for surgery is hearing preservation. The best way to retain hearing for as long as possible is observation. There are many published studies cited here on the forum that indicate this. In fact I was ready one this morning on the bus (
https://www.ncbi.nlm.nih.gov/pubmed/18559028 - I have the full paper). The last two posts in this forum of people trying to save their hearing with surgery are now single side deaf.
It appears your most concerning problem is balance and dizziness. Why not consult a vestibular therapist to see if they can help you. Your PCP can provide a referral.
Surgery has all sorts of risks such as single side deafness, facial nerve damage with some so bad that you can't blink, which require constant care or you could go blind, CSF leak, meningitis, headaches, additional damage and more.
In the words of Dr Micheal McKenna, "“The best treatment is no treatment, if you can do it” (
https://www.anausa.org/resources/videos/support-group-video-library.)
Do your research. This is one area where intensive research is worthwhile.
Given that your symptoms are fairly recent and significant, I would speculate your tumor is still growing. A series of follow up MRI will tell you both growth and rate of growth with time. Tumors tend to slow down with time and growth after four years from diagnosis is "very rare" (
https://www.bhtinformatie.nl/pdf/ingrijpen.pdf )
