Hi Hooded Singer,
normally I'd suggest taking words like I, and, etc out of lyrics but in this instance I think you should be adding them. So for example, the first line would be I wrote you a song but it's more like a scar.
Its a great opening line either way.
The last line would be but what you do now is none of my business. I think you need to connect the sentences like this to reinforce the mood.
In the second verse I'm not sure the line "but I lost my girl and it blew my mind works. I imagined the song being sung to the woman who left, but this suggests you are singing to somebody else.
Other than that I don't think it needs any more verses, its tells its story and leaves us wondering whether you get back together.
If you disagree please ignore me,
Keith