can porn addiction cause lack of emotions

Yes. A lot of SOs in the Relationship section claim that their PAs show almost no emotion in any situation.

 

Yes, they are on automatic mode when not watching pornography.

 

my ex gf complained I was "missing something". I had trouble connecting on an emotional level even tho I wanted to.

I felt like I was playing the part of a boyfriend in a movie.

So to answer your questions, yes

 

Causes depression. Depression causes numbness.

 

Absolutely, back in the day I was completely wooden, no real emotion and all around just numb to life. I still have great difficulty now but I'm at least getting some feeling back, which I haven't had since I was a child.