Can't figure out the actual cause of my ED?

Hi everyone.
I'm 19 and I'm suffering from ED from about a year.The problem is that I don't know what is the real cause of my ED. In my whole life I have watched porn just 9 or 10 times, so there is no possibility of PIED. I never indulged in over masturbation ( I've always kept a gap of at least two days between two successive masturbation). So, possibility of ED from over masturbation has also been cancelled out. I don't have problem of 'low libido'.
Now, there are only two things left which, I think, has led to this ED- (1) Traumatic masturbatory syndrome (2) Excessive fantasizing
I admit that I've indulged in some vigorous masturbation. Many times I used to masturbate with my face down . So, this can be a reason of my ED. Also, I used to fantasize a lot. This could've also contributed to my ED.

So guys, I have few questions from all of you-
what do you think has led to my ED ? Can excessive fantasizing cause ED? What should I do ?Will nofap help me ? ( Today I relapsed after 27 days).