Hi there Riouds, welcome to the forum!I think, if you've only been learning for several months, that you are doing really well to be playing such pieces. Of course, it really matters HOW you play far more than WHAT you play so it's difficult to judge by repertoire alone.As for the difficulty of the Ballade... Well, AJ Long is the one to talk to about that being our resident expert on it haha. But You have to understand that it's not only technical difficulties but musical ones and a certain high level of expressive maturity is required. I would suggest hunting for more medium term ideal pieces rather than getting too fixated on the Ballade. Try looking at some of the Chopin Preludes for example or you can give us an idea of your preferred kinds of pieces and we could suggest some.
I think the pieces you are playing are fine for the time you've played now.