A new diagnosis, with an unknown final outcome, is very scary. After all you have recently been through, the very thought that you might not be able to return to your chosen career would also be very difficult.

I see that you work in Labor & Delivery - one of the most strenuous nursing positions. You surely need a complete workplace assessment to see if your job meets the restrictions you have. I know it sounds like life is "piling it on" right now, but you may want to start thinking about less physical alternative nursing career choices...

I second @jimhd in his suggestion that it might be time for some help to sort this out. There are a lot of people here who can be a sounding board for you as you work your way through this - just ask!
Sue