Do you have trouble accepting any responsibility for not being successful in other aspects of your life too? Did your parents ever tell you that sometimes you lose because you're not the best team on the field?
Let me tell you in case they didn't: sometimes, especially in tournaments, you're going to find yourself playing against better prepared, better practiced, and simply better athletes. You're going to lose..... badly sometimes. It sucks. It hurts.
It's not because people hate you and are out to get you, it's because you aren't as good at the game as the team you played. It's a fact of life, not a conspiracy to get you. You will lose sometimes, especially when you make it to a national level tournament.
Suck it up. Grow up. Take it as a lesson. Be proud of what you achieved and try to improve on your weaknesses. Don't blame everyone else. Look at yourself.