WHY DOES IT DELETE ALL MY UI/FUNCTIONALITIES/UX OUT OF NOWHERE?

Every time I try to create an app, it feels impossible because Windows often deletes important code or completely changes the UI. When I want to go back, it's never the same. It's so frustrating!

HOW DO I FIX THIS? IM WORKING ON A SIMPLE CHROME EXTENSION FOR 3 DAYS AND ITS A HEADACHE WITH WINDSURF