Well I have not been what you called a "true" eunuch for very long. The damage I had done to my testicles did drop my testosterone quite a bit, which did reduce my addiction to sex and just about halved my libido. After the full orchiectomy, I was placed on Tgel but at first only took very little (2 weeks 1/2 dose). I felt no different than before. My doc changed me over to injections and they administered the first dose. and I did not really notice that much of a change with the first shot. I was left to my own devices and did not take the shot again for a while.
The funny thing is I thought my libido was low, but in reality it wasn't what I thought. Before all of this I was the one to initiate sex, and my wife would usually capitulate (even if she was far from being in the mood), she has never been the type who would hold out or punish me by withholding or not doing it for long periods of time, and if she refused it was for good reason. However, I can tell when she's just being "a good wife" and when she was actually turned on, which was far and few. I was enjoying the fact that I had no desire to initiate sex, but after my surgery she started to initiate a little more. I found that I may have lost what you could probably call the male libido aka light switch libido (ie, you walk by two pillows on the couch that only vaguely resemble breasts, which leads to thoughts of breasts, then sex, etc.) to more of a "female" libido? I didn't feel like initiating much, but was able to get seriously turned on with my wife initiating (just not so quickly).
We had been joking about putting some T on her (I do not suggest doing this), and well... one thing led to another. After about 3 days of a 1/3 dose of T, her libido... lets say became very male. Each time I was able to become aroused (sometimes it took a while), but I was able to perform. The twist is that due to the low T I had the sexual dysfunction of (well not as erect penis as when I was younger and) delayed orgasm. Some times taking up to 40 min!
At my last visit it was time for a shot so they gave it to me there, my libido has diverted more back to male (for now), and some of the (horribly) deviant thoughts that I had escaped came back, but oddly enough not my addiction to sex.
After I lose some weight I will cut back on the T to low levels, I liked that better.
As far as my wifes thoughts on the deal (long story). At first she was appalled. I approached her a year later and she was more receipting. Now she thinks (knows) I'm crazy, but she is accepting and trying to understand. I think she likes most of the changes so far.
with your wife (or other) and how long till you got there.