Hi. I don't want to sound hard but I don't think you are ready to play this piece yet.
But I'm not writing this to discourage you

. I'll give you my advice to improve (disclaimer: it's not a short nor easy way, it's not a magic solution, just a working one that requires patience and efforts): forget about fantasie-impromptu, at least for a while. In my opinion it's right now beyond your possibilities. Practice some easier pieces that you can afford during some time (some months or two/three years, that depends a lot on the person). These pieces will give you an enough background to play in a near future fantasie-impromptu but, please, don't try to build your house beginning on the roof. And also could be a good advice to look for a teacher who guides you, helps to choose the repertoire and watch your playing and progress
