I can play 4 pages of that piece now, after 5 years practice.
So do you start learning a new piece by learning one side of the hand first then combine them together ? I can play fluently when using either side of the hand but only when one hand is utilised. But when I start putting both hands together, I realise I have to switch my mind to and fro from treble to bass clef and then from bass to treble clef. And in a way, my playing often gets a lot of hiccups and hesitation. Do you often sight read while playing or you go along with your memory while playing in a way you don't actually really 'sight read' at all ?
I'm a bit of a maverick -- but then, I was an organist for years before I switched to piano, so I guess some idiosyncrasies are to be expected?I always learn all the parts together (left and right hand and, for organ, pedals). I have tried learning one hand and then the other, and for me at least it simply doesn't work.
I think, once you reach a certain level, it's best to play with both hands together.
Play with both hands slowly, just getting the notes right, not the time. You can always bring it back up to speed once you're more familiar with it.