From my personal experience you won't need a coach just yet, a coach is really good for decision making, changes in your mentality (i.e being more professional, not raging) and efficiency in your own practice i.e you learn how to learn better. There are all really really good things.
However they are all theory, things on paper that need to then be executed. Execution really comes with time and experience. You can know how to do everything but keeping it all in your mind at once (conditioning/trained reactions) and doing it consistently (muscle memory) come with just playing the game, over and over again.
You seem like an avid player rising quite alot in a short while, I recommenced you take some time out of the game to watch some really in depth guides. 'unswlolsoc' type it in on youtube, probably some of the best guides around.
Another piece of advice I can give you, take small steps to climb big mountains, rather than trying to get a coach and rise as quickly as possible, you should look for smaller achievements, sometimes getting good really fast isn't the best thing, you move on to the advanced stuff to fast, meanwhile your basics could still be improved.
On that note, I'm in Gold V, you should be looking to get to there as your next goal, if you want some tips or would like me to analyse your games, I'd be happy to.
