you have hit a plateau or you are simply not burning what you eat.
have you measured your body fat percentage? maybe you have gained muscle as well as losing fat so you weight will stay the same or even increase
are you training as intensely as you think you are? many people dont
i would drop the nuts and snacks its easy to over look calories
i think the whole low carb thing is also unhealthy especially for active person , no wonder you are fatigued.
have a read of Anthony Colpo Fat loss bible