Maybe you should try going outside and walking around for short periods of time while gradually increasing how long you stay out, and how far you go. Hopefully, with each time you will build up your confidence level. After two years you know you're okay, it's just getting past this fear and the only way to do that is by facing it. I wish you all the best and take care!
Sounds like the surgical repair was a total success. You have complete ROM, great strength and absolutely no problems getting around in your house. The fear of falling is normal and to be expected after such a procedure, but it should have resolved itself a very long time ago.
How much time did you spend in rehab? One of the biggest goals of rehab is to return the patients sense of confidence. Guess that didn't happen very well for you.
I suggest a visit to your ortho for a check up, definitely more rehab and if that doesn't restore your trust and confiedence, then you should seek professional mental health.
You are far too young to turn into an imaginary invalid, and you sure as hell do not want to become agoraphobic............you're on the path to both right now.
Get the help you need. That's my suggestion.
I wish you the best
Peace
Greenlydia