That's terribly sad - both for him and for you, as he has treated you badly. Maybe he didn't mean to but the result was the same.
Some people are not emotionally or pyschically or mentally ready to be a in real, adult relationship. W sounds to me like one of those people. Refusing to be the dumper in a toxic relationship is not a good sign. Honestly, you are probably better off in the long run being friends instead of romantic or sexual partners.