Your instuctor commenting that it may take you over a year to pass may also be taking into consideration the backlog of people waiting to take their practical tests. People are still having to wait months in some areas as everything was delayed and pushed back during lockdown, which I know is frustrating (I've been affected by it myself) but it's out of anyone's control.
I would try not to feel too disheartened by their comments, though. I'd imagine it can be difficult to accurately judge how long it may take someone to pass within the first few lessons - everyone is nervous to begin with but once you get more comfortable with driving you may progress quite quickly. Likewise, it may take you longer than average, but that's nothing to be ashamed of. The best advice anyone can give you is to forget what your instructor said and focus on the here and now. Don't worry about how long it may or may not take you because you'll get there in the end, and that's all that matters.
(Though as others have said, not moving out of first gear in four lessons is very unusual. You'd normally only spend one lesson, at most two, in first, getting used to the pedals and steering etc)