It might pay to have a look at the following thread.
Or just type erection into the show search drop down box.
Natural recovery from ED can take from a few weeks to never depending on the outcome of the type of surgery i.e. nerve sparing or non nerve sparing.
There are more options than just Viagra.
Also remember you do not need an erection for vaginal intercourse and the satisfaction can be out of this world for both of you.