Are the 55 carbs from veggies or a complex carb like oats or yams?
Have you had any others that know what full and flat mean look at you.
I only say this because if you have been low carbs for 3 weeks you might just be flat. Flat does not mean you look like a 12 year old boy. Your muscles will still hold some size even flat. What were you eating per day before 3 weeks ago? Were you eating 200 carbs a day? How has your cardio schedule been? Intence? Are you spent at the end of the day dragging tail? This type of info helps us. We can't say for sure what to do because we can see you. Go with your gut. I just always feel guys are more depleted then they ever think they are. Trust me here I'm been one of those guys a few times.
Best of luck at your show.
kdtl61