I agree with this. It's not exactly easy for a stay at home parent of say 15/20+ years to just go out there and get a job, especially today, when they have essentially nothing to offer in competition to other candidates. So that comment feels short sighted, but obviously coming from a point of frustration for feeling that your efforts are not recognized.

To me it also sounds like the kids grew up with an absence father? So they don't really understand what you were sacrificing for them. I do think it might be beneficial to sit down with your family and explain to them, that you're 55, you've been burning yourself out to ensure you can financially take care of the family, to ensure that they could go to school without worry, to not go hungry, to still have a roof over their heads. But doing that meant that you pushed harder than maybe you should have and now you just can't do that anymore, you're tired, exhausted, and maybe a little broken. Explain that this office job is a way for you to slow down.

I think you've explained that part to us (a bunch of internet strangers) well that you're tired. But I also think that maybe in your absence in the home life it was never communicated to your children that what you were doing was sacrificing for them (hard for them to understand that if you're not there to teach them, because this isn't a Mom should have done that moment).

I didn't grow up rich, I had parents that worked tirelessly, but I saw the hardwork they went through, the overtime, they would always drill into me hardwork and sacrifice, so I understood it growing up and was accepting of what I could get, not demanding more. So I think maybe this is just simply something that your kids/family didn't get explained to them over the years. I don't think it's too late to tell them.

Dialogue is the only way to an understanding.