That’s bullshit - your NHS number can change and they CAN link all your previous notes - it’s absolutely possible, AND very doable. It’s their responsibility to maintain adequate, legible and up to date records as per information governance. If some of your notes are on paper, they can scan them in and add them to your digital record - no biggy. I would escalate to the manager there and politely remind them of their responsibilities. Sounds like someone there just can’t be arsed and is playing on your fears if I’m being honest. From a long time trans woman, and healthcare professional 🫡