I advise people over and over again: You have to believe that you can win. It's vital to have that mindset. Yeah having a shitty matchup sucks dick, but if you enter a battle without a winning mentality, you by default already put yourself at a huge disadvantage from the getgo. You won't be able to think optimally due to all your bodily jitters and as a result can't formalize your game plan and at worst, choke away a winning situation.
By all means do not underestimate your opponents; Don't be a Laurel either and put all your opponents on a pedestal. This is much easier said than done however, so keep at it until you truly believe that you'll emerge victorious regardless of who you're facing.
You're welcome, niggas. Good luck to the remaining players.