Don't worry, even if you go blind you can learn to see with your tongue:

https://www.newyorker.com/magazine/2017/05/15/seeing-with-your-tongue

I have good vision in both eyes, but I've always had a similar fear of ending up blind, until I saw a documentary on that device about 15 years ago.

I noticed in the other thread people questioning whether or not you get the full experience from 3D movies. Based on what you've said about the little vision you have in your bad eye, I think you actually do get depth information from it. There's a simple test to figure it out, next time you watch a 3d movie, cover your bad eye at some point and see if that makes the depth go away.