He’s expressing how she’s destroyed their relationship despite his attempts to prevent them from breaking up. She destroys their relationship by not staying together and leaving him to twist in the wind. Now, he’s done with all of it, given up and sees her for who she really was. She, may as well be dead to him.

This is a straight diss track that’s both literal and figurative. It can certainly be taken as a “state of mind” where the aggrieved is tearing down the last vestiges of his mental connections to his ex. It can also be taken as guttural hatred for his ex.