Hi Cynthia,
This is really a tough thing to deal with. I'm Permanently Disabled so I don't have to worry about work, but there was a time when I was working and had to take a Leave of Absence to take care of my mom.
I think I'd talk to your husband's doctor and find out what he thinks. He would probably know a possible healing time line so you can present it to your employer as "What the Doctor Said". That can hold a lot of weight, knowing a professional is making that call.
Is it possible to perhaps work part time and have family or friends pitch in and assist you? Just my opinion but I think the Caregiver should have a "team" of supporters that can be available to spell you so you don't burn yourself out. From what I have heard, this healing time for this type of surgery takes minimum 2 months just to get back on ones feet. It takes 6 months to a year to really heal everything.
Of course there are things we cannot possibly prepare for, but also talk to your doctor about what can go wrong and what needs to be done about those things.
I don't know how empathetic your employer is, but this is a very, very intensive healing time and if he/she can grasp that, perhaps there is a way for you to take at least 3-4weeks off and then come back part time the next month and go back to full time, depending on what happens.
Hope this helps Dear.
Best regards, Rayn