Whatever you are doing it seems to be working!
Unlike me, who is currently struggling big time and actually slowing down again. Felt like I was working incredibly hard this morning and still didn't even reach an average of 15mph. It actually felt easier a couple of months ago.
I think I'll be celebrating my first year of cycling by giving up if I don't start feeling a bit better. Even wondering about my diet. I eat lots of carbs but really not much protein. Maybe need some more to help with recovery? Who knows.