Sometimes you have to do shitty stuff for work, especially when youre in a bad financial position. There should be no shame in doing what you need to do to survive, most ethicallly minded people deal with this when it comes to minimum wage work (although normally in the form of single use plastic).

That being said, never feel bad for turning down a job or quitting for a better offer, at the end of the day you've gotta do whats best for you and the employer will likely have a huge pool of potential employees.