Even with the bitmap tracing, it still turned-out really well. You can excuse yourself for "cheating" because you were mid breakdown while drawing, and people tend to have less patience for meticulous details while in that mood.
I guess one way you can practice making these backgrounds is by using the traced bitmap versions as a reference instead of using it directly, along with a version with brighter lighting so can see where all the walls are. Perspective is a bitch to learn, but to me I just treat everything as a cube, and that helps a ton
PS: I will sometimes just use real photos I've taken for my backgrounds when I feel a little lazy, so in a way I'm just as bad sometimes.