You can tell you really put a lot of time into this, a lot of effort into the mixing, but at the same time you can kinda tell you're pretty new to sound design... Without being harsh, you need to get some new drum samples. Mainly a tighter kick (with a clearer mid end) and snare. Also the hihat you're using sounds like FL default stuff. Also you really need to sidechain the bass to it. The melody clashes p. badly with the bass, and could maybe do with some more reverb? The synths sound pretty preset-y too, although the choirs were pretty cool. What software set up do you have?
Idk, my biggest quibble with this is that it sounds really uninspired and robotic. Dubstep should have soul and groove, it should feel dark and fluid. Right now though, it doesn't really sound like you have much vibe and soul or a high production value. Still, all the best finding your way in the world of sound design.