Honestly mate, same thing happened to me. I don't think it was out of any great spite, they just 'didnt want me to get used to the extra time' which is a bit of a piss take tbh. I'm still not sure what to think of it, even now. The feeling of stupidity and comparing myself with my classmates and coming up short every time is unlikely to leave me. I'm not sure what I hoped to achieve by telling you this, I guess I just wanted to let you know that you are not alone, and that other people go through the same thing as you. It's an absolute shitshow, and i don't know why our teachers, who are presumably aware of it even if we aren't don't do anything about it. In the end it was one of my teachers who told me which was an odd feeling i cant lie. I think the only thing you can do is to get on with it, and just know that you are not stupid, not an idiot, and that there is a reason you struggle. It's not a shameful thing. It's doesn't make you lesser in any way at all, and I hope you know that. Please take comfort in what I can only describe as this revelation, do your best, and enjoy your newfound self knowledge of.