Ok, so I abstained from jackin off for 1 week and lookin at porn. Normally I do it everyday.
My goal was to improve penile sensitivity.

Turns out, my erection was not that hard ...

Any explanations LG?

Don't know, DoggieStud,

Have no idea what the scenario was. And even so, breaking your patterns can result in all sorts of things. To measure penile sensitivity, you would have to hold some factors constant and change one thing at a time and then measure.

One week is nothing - try 45 days,
The Love Goddess

DS,
I'm not a MD...  but I have function issues due to spinal injury.  I agree with refraining from self-stimulation...  which teaches the body to respond to that type of stimulation to the detriment of partner sex.  
However, for me, it is about focus.  
I need the environment to be free of distraction.  No outside noises or distractions.  Music (no TV) that is soft & not drawing my mind away.  Soft lighting though I'm not sure how that fits.  Comfortable.  Temperature.  A bed, pillows, etc.  (No backseats of 71 Dodge)
A reasonably attractive partner who wants to be participating.
Condums can be a distraction.  The best ladies can put it on without a significant break in the action (I might loose some rigidity if too long.)  
Condom needs to fit right.  Snug enough to stay on but loose enough for some movement on the inside to give you friction.  Or a partner who will use female condoms.  

Focus on enjoying what you are doing...  Liking what you feel.  
Hope this helps,
skb

Disclaimer: I am not a physician. The statement was based on personal experience only and should no way considered an advice.

It was like it forgot how to get hard. Before I started hobbying I was watching porn and jacking off multiple times every single day. I can't remember a single day in the last several years where I didn't do it, so maybe junior started to feel neglected.

It should hopefully improve as you go longer without and get hornier. Especially when in the presence of a lady.

or even horniness.

It's a matter of retraining yourself to respond to a live female instead of porn and your own hand. It's something I have to watch about my own habits.

Well, if my mind wanders, hard becomes a sofee in short order.  Affairs of the day, music that distracts, focus on her like DATY, too long in changing position or digging out & applying a cover...  but renewed F/M stimulation brings it back if the focus is restored.  (distracting music or G-- forbid, TV, is the worst because they don't stop.)

It's not clear to me if this is what's happening or something the earlier respondants suggested...  perhaps he'll give mopre insight.
skb

reducing my salt intake has eliminated that problem for me. I've never had an issue with porn or masturbating too much, but did go through a brief bout of ED and soft erection.

I have had the same thing happen, but once I started up again it all worked fine.  Use it or lose it..