Michael - The best thing you can do between now and your surgery in August is to try and be in the best physical shape you can prior to surgery. That will make surgery and your recovery go better. You should try to rid yourself of excess weight without risking being too thin so that you have no reserves. Being in good aerobic shape will help you also. I did a lot of walking before my surgery, which was good because walking was the best post-surgical strategy to promote recovery. You could start doing Kegel exercises now since they will be an important part of your recovery to promote urinary control. Keep your spirits up as well because attitude will be important. Treat yourself to things that bring you pleasure. Enjoy lots of sex so that you're in as good of shape in that department as you can be. Most doctors suggest that although they can't get you back to better than before surgery, they can get you back to your pre-surgical level of sexual health.
If you have a good surgeon, the precision offered by the robotic surgery should minimize your side effects. I had robotic surgery in September and had almost no urinary incontinence. I was only out from work a couple weeks and resumed a heavy travel schedule after three weeks. I was up and walking the same day of surgery and pain was easily managed. Getting the catheter out on the sixth day was a major step toward normalcy. I wore Depends male guards for a while as protection against urinary incontinence, but didn't really need them.
Hopefully your doctor or medical facility will have a good program for erectile dysfunction. Most things that I have read suggest that it takes nine months to a year on the average to restore erectile function, assuming that nerves are able to be spared. about a month after surgery, my doctor prescribed a vacuum pump (Osbon ErecAid) with instructions to pump myself to an erection three times a day (in succession) to prevent atrophy of the vascular system and to combat penile shrinkage which occurs post-surgery. He also prescribed a dosage of 50 mg of Viagra to be taken three times a week to promote blood flow. I have appreciated this approach. Although I am still only eight months out from surgery and not fully recovered in the potency department, I sense that things are improving and I am further along than I would have been otherwise. So far, I have declined the shots that my doctor also recommends (Trimix) to almost guarantee an erection (that lasts about 90 minutes whether you need it that long or not), but I am reserving that option for the future if necessary. You are considerably younger than me (I am 54) and studies suggest that younger men have better and quicker recovery from the sexual side effects.
By the way, it was possible to have an orgasm in the first month post-surgery, manually without an erection. Of course, orgasms are now dry but the sensations are still there. One effect of this surgery is that you and your wife will need to develop greater sexual creativity, which is not all bad.
Yes, there will be somewhat of an emotional roller coaster. I'm on the other side of the big dips in the roller coaster track and life is good. I tried to not get excited about things in advance. This was never as bad as I thought it would be, so there was some energy wasted on worrying. The best part is that I am cancer free (with two post-surgical PSA tests to prove it). That is huge and would have been worth more than anything I have given up to get there. You've made a good decision and I hope you will be as successful in carrying it out as I have been. It's great to live in an age of good technology for diagnosis and cure. Good luck!