Sorry to hear your news, but don't despair.
I had non nerve sparing surgery in 2016. Within a few months I started to have some erectile response, and this news caused the consultant to prescribe Viagra (generic) 100mg. By the time of the first anniversary of the surgery I was getting maybe 80% of what I had pre-surgery, but only with the chemical support.
I changed to Cialis (again the 'event' dose - 20mg this time) around 1 year ago, as it has a longer half-life than viagra, and when Cialis came off patent and was approved by the local CCG, I switched to the 5mg daily dose. The result is now, nearly 30 months since surgery, I have 90% of my pre-surgery function 'on demand'. Without the chemical support it's still satisfactory for the intended purpose, but not as robust or perhaps long lasting.
My consultant Urologist describes such recovery as unusual but not rare, and says the biggest predictor of recovery is pre-surgery function. You will read on these pages that such recovery is impossible or only possible in the event the nerves were left in-situ. I offered this possibility up to my surgeon and got the shortest of shrifts in response, including the half-joking comment 'so the pathologist is in on it too'?
I would strongly agitate for the daily dose were I in your shoes. And don't despair.