Because you went to bed at midnight last night and you’ve convinced yourself that you’re losing an hour every day so you think you should be tired. If you usually wake at 7am, then you might have woken at 6am today because that’s what your body thinks is wake up time, because it’s the old 7am. It just takes a couple days to shift back. You haven’t lost a hour - it is still there. You’re just waking up early and can spend the time lying in bed resting, to get your body used to the change.
You’re tired because you went to bed so late and still woke at the time you usually do, which is an hour early, so you’ve had less sleep.
Yesterday, you gained one extra hour. It was a 25 hour long day. That makes you tired because you’re not used to that. But now it’s all back to normal, and there are 24 hours like every other day of the year.
If you go to bed at a decent time instead of midnight, and get up at your usual time - just go by the time in the clock - then you will get the same amount of sleep that you always get.
Can I ask, do you actually believe what’s being said to you and understand it? Or do you still believe you have somehow lost an hour and will continue to lose an hour every night?