My experience with and reading about
the pump is that using it is most important to keep the tissues viable while your body heals from the traumas of the surgery.
As the nerves regenerate, they will appreciate it if the penis muscle hasn't atrophied and actually creating an erection is not another issue.
Length will increase gradually as you use the pump - especially if you use it several times a week.
I also recommend using Viagra/Sedenafil Citrate (or another PED5) daily as it tends to increase general circulation in the area. (For 65 cent doses of Seldenafil, see alldaychemistdotcom.)
As for "too much vacuum," I would not cause myself more than discomfort - that is not too much pain. The tissues need the blood but you can "blister" the tissues if you rush things. My physician said it is best to just have frequency of "off and on" use of the pump each time you use it - letting the erection go up and down ten or 20 times for 10 seconds or so each session.
I personally find the pump boring but make myself do the exercise once a week and I do see some improvement every week.
I do have "soft-on" erections (without the pump) with frequent orgasms that are improving in erectile quality (both length and rigidity) each week. These orgasms are much more pleasant without the pump but they do require a lot more work than before surgery.
What I have read suggests that if the radical prostatectomy patient regains erectile function and continence, even thought the erections themselves are not usually quite as firm as before,
- sex lasts longer, is more pleasurable for both partners,
birth control is not an issue, and there is a lot less mess. You are so soon after surgery I would say take it easy.
Still, anything you do to stimulate this area without hurting yourself is probably a good idea.
If you want to become sexually active sooner rather than later, perhaps, in a while
, you might perhaps
look into injections as those who use them generally get their normal function back sooner than those who do not. (For excellent information on injections, look for Tamu's threads.)Good luck!