I noticed a difference within just a few days when I went gluten free. I found a sharp reduction in the symptoms of gas, distension, cramps, diarrhea, and that painful urge. Plus the fatigue for me had also been a big issue, since I also have MG, which has it's own fatigue. I found that within just a few days, I was back to my "normal" level of fatigue.
Stick with it, it will improve with time. I bet that if you really compare your symptoms now with your pre-GF ones, you'll notice you have had some improvement, even though it might be very tiny.