make sure & apply .gitignore

First, to check what files are you actually tracking
> git ls-tree --name-only --full-tree -r HEAD


Let say that you found unwanted files in a directory like cache/ so, it's safer to target that directory instead of all of your files.
So instead of:

> git rm -r --cached .


It's safer to target the unwanted file or directory:
> git rm -r --cached cache/


Then proceed to add all changes:
> git add .


and commit
> git commit -m ".gitignore is now working"