I suffer from it as well. Nothing I enjoyed before gives me any sort of feeling at all, it's a very strange and scary feeling when things that used to exhilarate me leave me feeling stale faced and empty. Even seeing my family which would literally pull me out entire depressive episodes in the past, can reach my inner feels anymore.
My existence feels so empty and hollow, it's a terrible feeling but im seeing no light at the end of the tunnel. Sometimes it feels like somehow, in some dark twisted way. I enjoy feeling this way, it seems that even when im in a situation where if i just was able to express some even a small amount of emotion and feeling, it could get the ball rolling. But I let negative beliefs (and they aren't assumptions) take over, I can't fight my negative thoughts like before because I always felt like they were assumptions. Like "everyone hates you" well okay let me look for reasons why I don't. But now when I get thoughts of these nature, I've been in this pit so long I believe it, ive heard the voices so many times I've stopped fighting them and let them become who I am. I believe I don't deserve happiness anymore, and even when I try I don't feel it so.
Soon I will be no longer, and the idea actually gives me peace and relieves some of this anxiety. I guess this is what it's like to be close to the end.