How to remove these huge green bars

Hello,

 

It looks like you enabled VCS integration and green blocks indicate that a new uncommitted line was added to the file you're working on. To discard changes you can select the rollback option:

 

 

Let me know if this is not what you're looking for.

 

Also, try to temporarily disable all third-party plugins. (https://www.jetbrains.com/help/idea/managing-plugins.html)