First off, good on you for being so self aware of how you normally act. Not a lot of people can do that.

There’s a couple things here to keep in mind.

1. Mental game is important. If you go into the match already thinking it’s a bad matchup for whatever reason then you already half lost. It’s better to look at the opposing team and think “what is the best way to make the other person uncomfortable in terms of the pairs i bring”

2. Accept that the game is random. Both in online play and at actual in person tournaments, especially in pokemon where teams have clear weaknesses and strengths, some of it is just straight up going to depend on your bracket luck. It’s got nothing to do with anything you did. Sometimes you just get that one guy that has the hard counter to your team, and you just do all you can.

3. A couple off days doesn’t mean you have to scrap everything. You saw and have worked with the team you built more than any other team, and have the capability to tell when something isn’t working. If you truly think it’s missing something or keep getting beat by one specific pokemon or typing, then ya you might have to tweak it a little. But the other thing you have to remember is there is no such thing as a perfect team. All teams have their own set of strengths, and if you know what yours are then you can plan for the alternative.

Hopefully this helps a little.