battery draining issue after installaiton of windows 11

I'm in the same boat. Brand new Lenovo Flex 5. Battery life was phenomenal. Was recc to download Windows 11 from a friend. 

Now, Everytime I pick up my laptop (every few days) it's dead. I used to get over a week out of my laptop before needing to charge. 

I'm passed by rollback day. I didn't realize this until 2 weeks after.