Post prostatectomy decrease in sexual arousal

Hi -

I'm new here, looking for some advice/help. Age 63, robotic assisted prostatectomy 4 months ago.  Went well according to surgeon who has done over 2,000 of these.  Last check psa was zero, to be checked again in a couple months.

Here's the deal. No erections since surgery, have been on a daily small (5mg) dose of Cialis. Not unexpected as surgeon said it could take a year for erections to come back. Without erection, it has been (very) difficult, but not impossible to stimulate myself to orgasm. This has happened rarely due to the difficulty. Recently, however, I'm not finding anything that is sexually stimulating that would allow me to reach that difficult to achieve orgasm. Not being able to get an erection is depressing, but not finding anything sexually stimulating is uber depressing. So... my question is this... is this part of the normal or usual process? Lack of sexual release causes muting of sexual stimulation? If so, will this, like the ability to achieve erection, come back given more time? Thanks for any help.

Phaedrus