Text Editor recommend?

I’m still trying to figure out why I’m getting ‘Warning: Cannot modify header information” across all of my files (no, no recommendations on here have worked), so can anyone recommend a text editor that will show the actual lines? When I use notepad everything is slammed together and I have no idea where one line ends and another begins. Trying to find the white space is line 42 is a lesson on patience when you don’t know where to start. And yes, I’m going to punch the dude in the face that recommended I move my blog to WP from Blogger. To much time spent fixin’ and codin’ and not enough time to actually blog.

Thanks in advance.