Honestly it might simply be a matter of “getting back into it”. I’ll give you an example, I started coaching high school football again. I did coach for 11 years but it has been close to 20 years since I’ve coached.
Now, I’ve given seminars in 21 countries and about 100 podcasts. So I’m comfortable presenting in front of people. Well the first practice I coached I was a nervous wreak!!! When I presented myself to the players I’m pretty sure that I sounded like an idiot.
The point is that the nervousness can be due to the fact that you a) still have high expectations out of yourself b) a competitive spirit c) don’t want to let people down AND d) that it’s been a while.
So your expectations, at this moment, far exceeds your competency. But as you will play more, the competitive game will get back to you and the nervousness will go away.
There are some supplements that can reduce adrenaline (nervousness, performance anxiety is an excess of adrenaline) and calm your brain down. The problem is that they can also reduce your performance potential by decreasing neuronal excitation too much.
Look at the following graph:
Too much arousal (which is what happens at the moment when you play) will lead to anxiety, tightness, thinking too much, overreacting, etc.
But too little arousal will reduce speed, reactivity, competitiveness, thinking processes, strength, power, etc.
So if you try to “bring yourself to the right of the curve” with “calming” supplements, you have the very real possibility of shutting yourself down.