I have flipped my sleep schedule

Kinda off topic, but how do I fix my sleep schedule?

When I started preparing 10 days ago for 2025, I wanted to give my all, and so I did, I studied the syllabus for like 8 hours, gave mocks at night, and the anxiety/stress kept (keeps) me up at night. Now I sleep at 11 AM to 6 PM, when I just can't keep my eyes open.

Already wasted 2 days trying to fix it by skipping sleep. Help.