This may sound a little harsh but go to the nutrition section of poliquins website and read until you understand. What is your goal? Fatloss im assuming? FInd a protein goal, eat it or die trying, start using smart carbs at the right times, get good fats from good sources and start eating like you give a shit, meaning, dont eat crap foods. Try and look up information on his bootcamp dieting. Calorie surplus? ANd youre overweight? Doesnt make sense. Get big or get lean but get moving.
no program... no matter how awesome... can dictate what your caloric requirements need to be in a state of lean body-mass gain. That's a function of your metabolism.
So, figure out how much energy you have to eat to maintain your current body-weight, then go ahead and "add by addition", and add 300 calories to that number, and hit those numbers by eating a healthy, well balanced, smart and comfortable diet.
Your body will gain muscle, and your body will lose fat over a safe period of time.
If you want to lose fat, eat a caloric deficit. If you want to gain muscle, eat a caloric surplus. What is a "deficit" or "surplus" for you personally? Good question, you have July and August to figure it out. WEDYEY? (What exactly did you eat yesterday)? Start eating clean. Put yourself on a diet (the purpose of your diet need not be fat loss, you could try to put yourself on a "maintenance" diet or a "+.5kg/week" diet). But you need to learn what food does specifically to YOUR body. It'll be a bit different for everyone. If you already have a diet plan, post it here and people will help.
By the way, are you REALLY 18%? or are you 25% but THINK you are 18%? Most new (and intermediate!) people underestimate how much fat they have. That said, at your height and weight that does sound about right.
Really, this isn't the worst idea in the world. Not sure how you're training now, but if you plan on starting the bulk in September, even a 6-week cut now could get you in a better position to build on and minimize the chances of extra fat gain.