mental management is your most important skill as a bjj athelete

For your self-image, know that you are already where you are. It might help at first to pretend you're like your favorite champion or role model, but if you don't truly believe it yet let your behavior drive your beliefs. It's a two way street. Your beliefs that you are already what you want to achieve will then drive and reinforce your behavior.

During film study, speak to your subconscious using the right language. Visualize and feel-image the desired outcome.

During rolling training, stay in the present process. At this point, all the visualization and feel-imagery should be trusted to your subconscious.

Observe non-judgmentally what is happening.
Stay in the now, in a state of "being". Fully experience it.
Repeat 1 & 2 iteratively.

One mistake that people will make here is they think that they're in the state of now, but really, they're thinking about what their opponent is going to do next, and the immediate future of the positions that they're in. If you're thinking into the future then your subconscious is allowing your opponent the opportunity to advance. Don't make this mistake. Be in the now. Observe non-judgmentally, and your subconscious will execute your desired outcome.

In some sense, it's a combination of a lack of technique and a lack of presence. Work your techniques, visualization, and feel-imagery to prepare your subconscious, but step out of the way when it's game time.

Replacement attitudes.

"Hard practice? Got fucked up? No worries. 1% better."
"Opponent's fucked you up before? Doesn't matter, that's history. Now is what matters. Every roll is a clean slate, a challenge."
"Opponent is at a level higher than you? So? Now is what matters. Every roll is a clean slate, a challenge."
"I'm not going to accept you settling into this position."
"I'm going to get to my position and start working."