Look back & remember what is in your mind when playing? Do you enjoy the games or think so many thing which makes you very nervous.
Coz, (still on the same my 1st tournament). Btw its group format, 3 double team, 2 team win mean the company they represent win & move to the next round. On the final, we meet a strong team (obvious). One of them are ex national player. Basically whoever meet the champ are losing. So we kinda thinking what combination should we use. At that time coz im the new guy & play with any of my team just for short. I said, let me take the champ, strengthen the 2 team. Without any burden of losing the games, funny i can play more relax & perform way better than the early match. I still lost tho but can still keep up & give some pain to the champ ass.
If its your mind that messing you, change your mindset. Dont think thing that far away like winning or losing but think about getting the next point. Regardless win or lose just do your best & aim for the next point & then next again, till it end.