I am so sorry this happened to you. I have been through a RD this past year myself. It is very frightening and completely understandable that you are worried. There is nothing quick about the recovery from a RD. I have a very complicated situation and was so severe I couldn't have gas, I had to have oil. My situation is different medically but I know the fear and frustration that comes with a threat to the vision. The recovery is typically gradual from what I have learned and am experiencing myself. If you trust that you have the best doctors possible, follow their advice and be patient. I know it's hard and it is very hard to adjust to the vision, talk to those who have experienced this too when you need some reassurance. Others around you may not understand how difficult and frightening it can be but there are plenty of us who do! I now know several people who had the gas bubble and they had 95% of their vision restored within a year. Take care.
I had the same surgery as you 4 years ago. My gas bubble broke up into small bubbles after 2/3 weeks then went. The vision gets better during this, almost like looking through a fish tank emptying itself of water. Hang in there, things will improve. My eye sight is perfect though prior to the op I was given no guarantees. That was at Southend Hospital - Moorfields is up there with the best in the world, so you're in good hands.
In a complex situation you need honesty not on-line reassurance. I understand your fears. But you need to address these questions to your eye surgeons.