How to lose the fat but not the muscle?

Good for you for working so hard.

8 pounds sound like a lot of mass to have gained in such a short time.

Try to look at your diet, and reduce amounts of carbs and fats (don't get rid of them altogether, especially while you maintain such an extreme exercise regime). You didn't say how old you were, but I suggest taking a one time consulation with a professional dietitian who will look at your diet and let you know where you stand.

Plus, sometimes it takes the bosy mnore than 6 weeks to get used to the fact that there's a new boss in town so to speak, and it acts up a little. Don't lose heart!

Keep doing what you are doing. The added muscle is a good thing. While you are building muscle you are also burning mucho calories, which will lead to losing extra body fat.