samadabad, I am going on 20 months since a robotic laproscopic radical prostatectomy. (I was just short of 64 when I had the procedure.) Unlike you, I had no post-op pain (except for the discomfort of the catheter), and (hallelujah!) never any incontinence issues, ever.
As to the ED, the bad news is that, although I never had issues at all before the surgery, and although my surgeon assures me that all nerves were spared, 20 monhs later, there remains a major deficiency.
My doctor prescribed Cialis, but I have used it very sparingly, due, first, to the fact that it seems to have no effect whatsoever, not even in the slightest, on the problem, and, second, to the side effects (principally, spasms in the muscles between my shoulder blades and spine, which is quite painful). He also wrote a prescription for -- and my health insurance carrier agreed to reimburse me for -- an Osbon Esteem vacuum pump, which is useful to keep blood flow (and hope) alive. However, the "regular" constriction rings that come with the pump were just too painful to allow intercourse: when all thoughts are on the pain, it is difficult to enjoy an intimate moment.
Thank goodness, on my own, I discovered a new and barely publicised accessory for the Osbon pump, a different kind of constriction device caled "Surerec." Surerec is all but pain-free, and orders of magnitude superior to the standard constriction rings.
Unfortunately, my insurance carrier does not recognize the Surerec as a medical device, and the little rings cost (depending on where you buy them) $25 to $60 each. (There is a quantity discount if you buy four of the same size at one time.) They come in four sizes, but Timm Medical gives no guidance on what size is appropriate for whom, so you have to take chances and order, and throw out every one that is not the right size (nonreturnable item, of course), at $25 or so per experiment.
The good news is that with the Surerec, my wife and I have been able once again to enjoy full marital intimacy. There is nothing spontaneous about it, nothing like the spontaneity that we could enjoy before the surgery, but intercourse is possible, which it was not for the first year and a half after the surgery before I discovered the Surerec accessory.
I hope you find this helpful and encouraging.