"Mastery Demands Falling In Love With the Plateaus" -- Dan John
I think I heard Coach John say this on his last interview on the Fitcast. I could be wrong.
In any case, it's one of those little pieces of wisdom that is worth not only hearing, but really thinking on.
As much as we want it to be, progress in anything is rarely a continuous thing. You will have period where you improve rapidly. You will have periods where you don't improve at all. You will even have periods where you get worse (understanding the U-shaped Learning Curve is critical here).
All of these things are okay. If you want to get really good at what you're doing, they will all happen.
Just enjoy the ride.