If an employer hires you for a part-time job that is actually a full-time workload, or has you do the job of two people, I don’t think you should feel guilty about leaving them as soon as you can.

Depending on your circumstances – consider ghosting them or searching for a new job during off hours. You might just leave and provide them with resources to hire a contractor if they need a replacement quickly. Or, give your two weeks notice if that seems like the way to go.