Low libido and lack of satisfaction

I have this sexual problem. For the past couple of months (I say it started sometime in August 2010) I've noticed that my libido has been slowly eroding and has reached a point where I feel dead. I tried to ignore it as a temporary problem, but it just wouldn't improve. Masturbation started to feel less and less pleasurable (I don't have a partner and never had one), porn started to excite me less and less, and started having less and less sexual fantasies. Things that used to turn me on just won't do it for me any more. I don't have trouble getting an erection, I still have sexual drive, but I can't make anything out of it. Whenever I masturbate these days, it just feels wooden and I feel desperately dissatisfied. I just can't reach proper level of orgasm. I'm a 23 year old man, so I shouldn't be feeling like an 80 year old already.

This is especially puzzling and frustrating for me because my libido used to be at a level where I felt like a completely obsessed sex addict. Back in time before the problem started, I remember once spending 5 hours on a sexual fantasy without the help of any porn in middle of writing an important essay. I would spend hours everyday on porn and sexual fantasies in my head. Many nights I couldn't sleep until I masturbated. I could be exhausted, hungry, sick with flu, etc. and I would still have the energy to masturbate. I was also vividly addicted to pornography and so far I have collected tens of thousands of pictures and videos on my computer that takes up 130gig of my hard drive. I felt so hypersexual that I actually thought about seeking help here for sexual addiction, but now... it's the exact opposite. My sexual satisfaction is so low that I'm feeling extremely depressed.

I've read things online that might give some clue as to the problem I'm facing. I've read that depression can cause low sex drive, but I feel much less depressed compared to few years ago and depression back in my teenage years never really effected my sexual satisfaction. My diet has been almost same, so it can't be that. I've had high sexual satisfaction on times when I didn't even eat properly. I'm exercising more than I used to, so that can't be the reason either. I mean, I really have no clue why this suddenly happened to me. Could it be that I stopped taking Adderall? I was on them for about a year before I quit them last year, but I have hard time accepting that as an explanation because I don't think my sex drive was influenced by them.

I think I should also mention that I also feel less excited than I used to. Music doesn't excite me the way it used to and I just feel a bit apathetic. I used to feel great deal of anxiety and anger, but those emotions seem much more subdued these days. But really, they are somewhat minor changes compared to my sexual problem. I feel like I just suddenly got castrated or my dopamine pool is empty or something.

how do you feel when your around women. could it be possible that you just need the physical contact instead of the visual ?

Slightly aroused, yet uncomfortable. Maybe you're right, but if I can't get aroused visually, wouldn't physical contact be any better? Besides, it's not like I am going to have a chance to get physical contact in any way.