Hi,
my father had a similar diagnosis to you back in 2009, he opted for surgery. They could not spare the nerves. He is cancer free, with some stress incontinence and ED. But he is happy because he does not have cancer. It may be that your surgeon could save some nerves on rhs which may improve your chances with ED.
start kegal exercising now if you haven’t already, my father didn’t, then really struggled post surgery with incontinence as he didn’t know what to do and couldn’t feel anything.
whatevet you decide to do, make sure you are fully informed.
All the best...