Quitting new job? Seeking input

I started a new job 3 weeks ago and am already considering quitting.

For context, I was a stay at home mum with my toddler before accepting this job. I decided to accept this job because my severance pay for my previous job is about to run out and I wanted to ease back into the workforce as my daughter starts going back to daycare.

I have been working a program management position for the last 3 weeks and am already considering quitting. This is a part time position that is covering someone who recently went on maternity leave. From the beginning, I have run into all sorts of issues.

For one, this position was advertised as a program management support position. However, on my first day, I realized that it was really intended to be a manager role, where the person hired would be responsible for making decisions independently. I have gotten dozens of emails from people asking me to make decisions that I don’t feel equipped to make. I feel under qualified as I have never been the manager on a project before.

I never got to have an official handover with the person who previously occupied the role as she had her baby a few days before I started. This means that, even though I am only paid for two days of work, I have found myself working significantly outside of my work hours to try to catch up and make sense of where she left off. There are many records that are missing from her work and it is hard for me to figure out where she left off on things and why she made certain decisions and no other staff member seems to know.

I know the obvious thing would be to talk to my manager. However, I only met my manager twice. He went on PTO after my second week and will be gone for the next three weeks so I have no support. There is no one replacing him or there to give me guidance while he is gone.

My husband thinks that we will be fine for the time being under his salary, while I try to find something that might be a better fit. I’ve just never quit a job so quickly before and am worried that I am making a rash decision.

Any advice? Has anyone ever been in a similar position?