Weight Gain & Foggy Thinking Are Symptoms. I'm On Synthroid,

Weight gain & foggy thinking are symptoms. I'm on synthroid, 125mg 5 days/wk & 137 the other 2. I was better with 4 days at 125 & 3 at 137, but then the numbers are too high when the blood work comes back. I'm in the Air Force and my fitness test is in 4 weeks. All the healthy weight loss options help with 4-7 lbs and then it comes back. I count calories, work out 3-4x/weeks, eat less sugar & more protein. In the past week, I only worked out 2 times & gained 4 lbs. My waist is too big to pass my fitness test, which then leads to administrative discipline. Is there something else that could be?