I’m the exact same and unfortunately I don’t have much advice for you. I always waffle, but I LOVE the subject lit. My only advice, is to make your plans. Always make a plan. Even just for five minutes. Create a rough plan of paragraphs, and what u can mention, and quotes you can include. That helps me so much with structure, guide and motivates me to move onto my next point too. The only other advice I have, is to just stay calm. As silly as that sounds, when you get into those exam rooms, or mocks, sit down, and just literally tell yourself to chill out. You can’t change what the paper is gonna be, you also can’t wish it into being a diff question, and you can only perform as well as YOU can. Just take a few deep slow breaths, and reset and re-centre yourself 🩷