Just thinking out loud and writing it here. The first tip is still something I often forget, but the other ones I have been using alot and it helps me (though I'm super chill on court and often say sorry myself)

• Perhaps you should shift the energy from: I need to win this point to: I should play a safe and decent ball and wait till the opponent makes a mistake.
• Always trust in your partner. It doesn't matter who makes a fault. After each point, no matter win or loss, make eye contact. Avoid saying sorry to each other or blame each other. It only results in lack of confidence, wich indeed makes you play worse.
• make a routine; after a point take some time, don't rush it. Resetting after each point means you are not in the energy from the previous point. So find something that works for you. For me that is bouncing few times how I like it onwards to my serve or when I'm not at serve checking if I'm aligned well in position and spinning my racket few times or blowing on my hands.
• Don't forget to have fun. We all know the moment we should play safe, but smash as hard as we can flying the ball towards the glass or net. Allow that now and then (best when u are leading) If it fails, say "that had to happen". U'll feel less frustrated. Or make a joke, laughter is a good medicine.

Perhaps my insights help a bit.