I don't think your prior surgery (pudendal nerve) would have any bearing on the libido aspect, and your testosterone levels seem to rule out that as a cause. Due to the nature of the problem, I would certainly speak openly and frankly with your physician. As David said, I would begin to looking into other sources of the problem like supplements and medications as well as other things such as stress or emotional issues. So many times there are outside things that can cause a loss of libido that have absolutely nothing to do with medical reasons.
Best of luck.
You are beating back cancer, so hold your head up with dignity
Age 58 at Diagnosis
Oct 2006 - PSA 2.6 - DRE Normal
May 2008 - PSA 4.6 - DRE Normal / TRUS normal-Gland 38 cc
July 2008 - Biopsy 4 of 12 Positive 5 - 30% Involved Bilateral (Perineural Invasion present at base) - Gleason (3+3) 6 Stage T1C
August 23 - Bone Scan - Hips, Spine and ribs marked uptake - X-Ray showed clear -Hooray
Sept 9 2nd DRE - questionable - TRUS...shadow in base - Gland now 41 cc
Robotic Surgery Sept 18, 2008
Pathology October 1, 2008 - Gleason 7 (4+3) Staged pT2c NO MX - Gland 50 cc
Seminal Vesicles and Lymph Nodes clear
Positive Margins Right Posterior Lobe
4 tumors in prostate - largest being 6 cm
PSA 5 week Oct 2008 <.05
3 month Jan 2009 .06