I love that someone brought up this topic. It might be the only thing I can comment on. HAHA. I do not play fighting game competitively, but nerves are something that can be found in any sport or hobby where you compete against others. I learned to first control my nerves by playing competitive paintball, but then had to master it when I became ranked pro playing foosball. Yes do not judge me, it is a real thing. I used to be the same way, for the longest time. I am going to skip over the paintball aspect and go straight to foosball since that had to be something that was more forced than natural.
To me there are two keys to getting over nerves, the first is to force yourself to play in more situations where nerves can be a factor. If it is as simple as going to a local tournament, playing a friend for money, or just finding someone new that you are nervous to playing against. You need to get familiar with playing nervous.
The 2nd is to recognize them when they start to creep in, and come up with something that helps you get over them. For me it was breathing properly. A good friend of mine it is making the same stupid joke in a pressure situation. When you setup a routine in a pressure situation your body learns to relax from that routine. This is why you see so many Golfers do the exact same thing before they make a shot. It gets their routine going and their body relaxes. I always suggest breathing personally, I think that it helps in just about all situations, and it naturally helps your body and mind relax.
There is also a book that has helped many people "The Inner Game of Tennis" I would highly suggest it. Yes it is a tennis book, but it can relate to just about anything. Has great tips on controlling nerves.
Hope this has helped!
