https://www.chess.com/forum/view/general/how-to-stay-calm-during-a-chess-tournament?page=1
My posts are currently in comment #25 and #28 if that helps 
In short, you'll be fine if you just take your time and try to take in the experience. Your rating on chess.com is higher than the average OTB player, so you should figure that at least half are more nervous than you. 
Great thread, thanks for the heads up. I'll have a read when I get a moment today.
Being nervous prior to a tournament is normal. At least it used to be for me 50+ years ago when I played OTB in USCF events and in USN fleet competition. You will get a kick out of this. I did not have trouble sleeping the night before the tournament, but the morning of the tournament the nerves would hit and I'd be sitting on the "porcelain throne" for an hour or so purging every meal I'd had for a week, or so it seemed! After that, I was fine, and I was ok throughout the tournaments. Lucky for me it happened prior to the start of the match, and not during the match! I don't know why this happened. I guess subconsciously I was just worried about being competitive, that I belonged in the match. I also used to play 3 to 4 simultaneous blindfold games, but in those I never had the nervousness I experienced in regular OTB games. I've read that Bobby Fischer lost several pounds during every match he played due to nerves, so you're in pretty good company!
Play more often. You will always do yourself justice in the long term. And even if you happen to blunder a piece in a blitz tournament, I think you won't be alone.
If you really are uncomfortable with your games/results I think FIDE will be obliged to remove your games and rating from their webpage and databases if you wish, especially under new GDPR guidelines about retention of data. But as others have said I would hardly be worried about it.
It seems you (and many others as well) attach a great deal of self-worth to the results of your chess games and tournament results. Fixated on the Fear of Blundering in Public and being exposed as a blundering chess patzer, and therefore both stupid and pathetic. Oh the shame and humiliation. Who, indeed, could live after such agonizing misery and pitiful suffering?
Okay, I lathered it on thick. But it's for the purpose of getting you to see the utter ridiculousness in your self-created anxieties induced from an over-abundant imagination.
Now go forth after a proper waste elimination before an OTB tournament game and blunder in psycho-emotional peace throughout all your games.
Evening before start: at least 5 IPA😉, no sex, no chess or vice versa.
Day of tournament: good breakfast, no chess, no sex, no IPA, but a good toilet. One hour seems a little bit to long.
On the way to the tournament: no sex, no... But chess thinking, which opening. Do not forget a pencil for notation.
The game: no sex, no...., Play your style, avoid time trouble, fight like a lion, do not give up to early. Blunders, yes you will make some, your opponent, too, sometimes he will see your blunder, sometimes not. Spectator are stupid, your game is not exciting for them and they are lower rated like you. And they are air, because you fight against your opponent. Blunders are always sacrifices 😏. I sacrifice always pawn in the opening, I call this a gambit.
After the game: now it is your time, IPA, sex, food, online chess on chess.com.
🤺⚔️💪🥇👏😂😂😂😂
Yes, good advice. 2D Vs. 3d . Capture figures with your hand, smelling your opponent last food like garlic. Sounds in the background and so on.
And if you are a taff guy, watch your opponent in his eyes. Sometimes you can see his thoughts or fear.
Be cool. Play with a pokerface, and sometimes a little bit acting. You will see wonders on the board.
for me that is impossible to avoid the nerves, it would be like the first time you enter to a tournament, the nerves only goes away after you have played many tournaments, but well... we are humans, we have emotions
Yes. We have nervs and adrenaline. And this is good. You will cool down during the game.
Excellent advice, cheers all. If I can use it for weight loss then this will be a superb bonus!
Just went to a new tournament (I've never been there before) and have real bad anxiety. I couldn't find where it was, and was worried out of my mind. I found it though, and I had a blast playing against real competition: (15-1600 USCF) I'm around 700 now, but I just started bringing it up so it should be around 1300-1400. I was so stressed my opponent (who saw my hand shaking as I held the pieces) asked if I was okay. Once I got over that it was fun! Good luck with your endeavors, OP.
I'm nervous when I play lower rated opponents -- against higher rated opponents (with pretty much no stakes) I tend to go wayyyyyy better. I have a plus score (otb) against a 2300+ FM in rapid and blitz out of at least twenty games, but I also have a minus score against an 800 (I lost to the 800 hen I was a 1200 -- a 400 point upset!)
Just enjoy the game 
After just over a year getting back into chess online, I feel that I'm ready to move into the world of OTB. I've got my FIDE ID, and there's a rapid tournament in my city in a couple of weeks. The problem is, I'm worried I'll be completely overcome with nerves. I even failed to sleep before a casual tournament a couple of weeks ago, and one of the reasons why I gave up serious chess as a ten year old (I was ranked top 20 in England for my age group at my peak) was that the nerves were destroying any enjoyment I was getting out of it. It seems like 30 years later nothing has changed! Does anybody else get this? Of course, rationally I realise that absolutely nothing is riding on the tournament, but for me the fear of not doing myself justice is all-consuming. There's already the issue that I'm not so great when playing fast time controls, but the prospect of blundering a piece in public is something that I find too traumatic to contemplate! Ridiculous I know, but if anyone has any advice I'd be VERY grateful!