I spent months trying to learn a righty played as a lefty. ie Strumming upwards etc. I did this in isolation before meeting up with my future band mates to show each other what we had learned. I was miles behind with my effort and realised i was doing it the hard way. A friend restrung the guitar and i had to begin again from scratch ie learning to play chords etc. next time we met up i had improved greatly.
I think my mistake was to hold the guitar as a leftie instead of as a rightie. I blame the isolation of my bedroom for this and the unavailability of the internet,affordable lessons and a small brain. I know some people have learned leftie on a rightie but imo its much harder. Unless you play your own stuff your way.