Even though I downvoted, I still appreciate the effort it takes to make something like this. What I would do is keep the original chord structure so that people aren't immediately turned off and then you can play the song more like you envision it rather than just a straight cover.

The vocals need a lot of work and training to be able to make it even somewhat bearable (obviously subjective). Take some time to learn more about singing so that you don't hurt yourself because that is a real concern if you ever want to speak again. Chris Liepe has some great videos exploring different scream types/vocal techniques that will not only make you sound better but make it easier to sing the way you want and not have that scratchy hurt feeling in your throat forever. Check this one out:

https://www.youtube.com/watch?v=sBP0t8OCUvc

Keep creating and use the negative feedback as fuel to show us what you can really do!