Some good rules of thumb to apply to mixing.
1. Lowering the instrumental is never a bad thing. You can lower it by a limiter, which is what I usually do, or you can use the knobs for volume in your DAW. Usually lowering it to -6 db is helps.
2. Make sure that your vocals are compressed after EQ. If you compress then EQ, you will have uneven vocals, which will make them sound muddy.
3. It seems like your EQ may need to be improved by reducing some of the lower frequencies (around 200-500hz.)
4. I can tell that there's no ceiling set to this track and no limiter on the master track. Limiters help with creating ceilings for certain platforms like SoundCloud. Soundcloud requires a -1.5 db ceiling to prevent clipping.