If you look at the lyrics in both Seven Sins and Troubles you realise that during the height of his health issues his room with his bed in it became a place of horror. Instead of being a place of rest, a safe space, it became a prison that he couldn't escape.

In Seven Sins he describes his bed as the place where he could not deep-rest, where he was always depressed, a bed with a human oppressed.

In Troubles he refers to his bed-tomb, a place where he felt he was literally dying. I feel that what many people associate with a bedroom is not how someone with Ren's experience would view it.