The Otherworld I Reincarnated Into Was a Slum: Starting a Slow Life from Rock Bottom

I woke up in a room I'd never seen before. Cobwebs hung from the ceiling, the walls were falling apart, and a draft made it chilly. Where am I? "...Ugh, that stinks!" What is this smell!? I moved my uncooperative body and looked around. The moment I realized the source of the smell was me, I also realized I had become a baby. That's not what we agreed on!! Due to a certain mistake, I was supposed to be reincarnated into another world—but then another mistake landed me reincarnated as a baby