Feeling quite scared and very shocked.

Your symptoms drinking, toilet, tiredness and genetics all sound very familiar
But it really isn’t the end of the world a shock yes but it can be so well managed now and there is also so much help from the nHS
My closest friend also slim and full of beans became very unwell two years ago She was hospitalised and diagnosed with Type 2 it’s been a rocky road as it’s been hard to get her stabilised she was up and down although she followed instructions to the letter however two years on she is so much better the Diabetic nurse rings her regularly every few days and titrates the insulin as and when necessary She looks so well is full of life and her figure is even better than before She can eat anything within reason It’s about careful diet not too much of anything She counts carbs not calories
She was very very poorly when first diagnosed it came out of nowhere
Please don’t get too downhearted

I'm sorry you've has this bad news. Is this the only test you've had? I ask because my 91yo mother was also diagnosed with diabetes. She is overweight but had never shown any previous signs. She was very concerned but a follow-up test came back as normal and since then, two or three years ago, she's never had another suspicious test result.

I don't have any experience of pre-diabetes myself but I imagine you will need to see the doctor and discuss it.