According to the information you provided, the lines you quoted seem to be spoken in a certain novel or web novel. In novels, characters often experience some self-doubt and struggle to realize that they are not real humans but some other existence.
However, the specific meaning and background of this sentence needed to be determined according to the context. It could be a mental state, a metaphor, or a part of a particular plot. Therefore, more specific information was needed to determine its meaning and background.
At the moment, there's no definite information about more Dr Stone manga. It could happen if there's enough demand and the creative team is up for it. We'll just have to wait and see.
It's hard to say for sure. The decision often depends on various factors like the popularity and sales of the original series, as well as the author's plans and the publisher's strategy.