Okay, so you have some specific challenges. if you're working in a customer facing job - wqhy can't you write down what people order? I have a terrible short term memory but I never had a problem as a waitress as I'd just write it down and then take it to the kitchen.
Having said that, if your short term memory is this poor and you have consistently struggled to learn, I would be seeking help. I'd go to yoru GP first. A key benefit of assessment and diagnosis is that you can also then access tools to help you manage these challenges better.
You also need ot be realistic. You can't be a police officer without a fairly good short and long term memory. You need to know the law, you need to understand lots of procedures, you need to be adaptable.
it sounds to me like jobs tha tmight work better for you are ones that are more practical/hands on, and repetitive. And/or jobs that are quite process driven but in a way that's clearly articulated and documented. eg shelf stacking where it's all labelled and marked up so that you take boxes to the relevant shelf and unpack. Or garddening where you need to do a specific thing. Or delivery driver where you're provided with a route, a map, and clearly labelled packages.
You have been a SAHM and I assume you've done that successfully so those informal/ selfemployed jobs doing the work that families need but don't always have time for, might work for you - cleaning, housekeeping, cooking, dog walking etc.
Perhaps try doign some volunterring as a helper only at placse like brownies or guides - see how you cope in those environments when you can be supervised.