It sounds like you have too much going on so it is going to be too hard to talk through each separate aspect. The advice i can is that less is more, tighten up the bass sound you want and keep that as the main element. You want your kick and snare to punch through so make ysure you separate your basses into the subs and highs. sidechain the subs tot he kicks and the highs to the snare. Use hats sparingly, you will be surprised how much dnb is very tight with little reverb. if you want some tight drum samples ive got plenty i can send your way that will need minimal processing that you can have a play with, pm me
for the mastering side, mastering is more taking away than adding. if you want the sub to be punchier lower the mids slightly to give them more room as opposed to boosting the lows. The master compressor doesn't fix a bad mix it will only bring out problems more that need top be adressed in the mixing stage. You may find your track will sound instantly punchier by making everthing below about 180Hz mono, however in some cases you will find this can hollow out your track considerably. Mixing and mastering is hard to talk through as it completley varies depending on what you are working with.