I consider myself an average to below-average racer. I'm not as young as I used to be and my reflexes aren't as good as they used to be.
I started using a controller and now I use a steering wheel.
You may wonder why I'm giving you my history and it's only to say this:
You may find that shifting actually makes you a better racer and actually gives you better control. A friend of mine who is a real life race car driver told me that when I started doing it, I would never go back to auto.
I was sure he was wrong and that he vastly overrated my abilities which I knew to be pedestrian.
To my surprise , i found out quickly that he was correct.
I mapped shifting up to flicking the right stick up and I mapped shifting down to flicking the right stick down.
I was instructed to go to a track that I'm comfortable with and take a few laps with shifting. I knew within the first two laps that I would never go back to auto
Shifting will help you control the car so much more. You've heard people talk about short-shifting to help them conserve fuel, and that is a big advantage. But, I find the greatest benefit is in braking and coming out of turns with better control and acceleration.