Erection by touch - QUESTION

Hi all,

I am 45 and I have been a porn addicted since I was 23, when I first had internet and could see in images and videos all fantasies I have had since I was 13.

Now at 21 days of rebooting i have already seen unbelievably good results, especially in my attitude toward life and other people, especially women.
I have experienced the dreaded flatline, and chances wanted that after few days I made the decision I slept with a woman I have always liked. I had to tell her about the flatline, I could not have sex, but that seems to be normal, I guess for that I will have to wait a while. In the last few days though, after interacting and flirting with real women, I felt the need to masturbate thinking of them, and I believe that this is what could be called healthy masturbation, I was not thinking of anything extreme, just kissing them or making love to them.

I have had a life of sexual frustration, as my erections have often been unreliable, and this, together with other issues, contributed to my anxiety and sometimes depression. I was lucky to have occasionally some amazing sex, so that I do know what I am missing, but then in many occasions I could not get any erection, with several women.

I came across porn dependancy first when I was 27, and I thought that just not binging on it any more would have sorted my problem. I thought my problem was my femdomination fantasy rather than watching it. Certainly not binging helped a lot to have some form of normal life, but recently I have realised that I was still a porn addicted, and I used porn, instagram and twitter images etc... as a habit and a form of soothing.
This has led me to a very unfulfilled life, not only with women, but in every aspect of my life, as it takes energies off you and makes you feel different and inferior to others.

After this due introduction, my question for whoever might have some medical/scientifical information is about erection by touch.

I did the test, and that is when I clearly saw that I was addicted: no erection whatsoever by touch, while I got excited as soon as I matched it with images of femdomination taken from the thousands of videos I have seen in my life.

I wonder though, should erection really come only by touch? I honestly do not remember when I was young and started masturbating, isn't it actually normal that you are fantasizing about something? When I say fantasizing I do not mean about all the porn you have watched, but thinking of a real woman, of her smile, her smell, or even making love to her.

I would be very grateful if you could share any medical/scientific info on this subject.

thanks