Question about HOCD and gay porn [1]

Hi, I'm a straight(I hope) male that has had HOCD for about 5 months, I have diagnosed myself with HOCD because I can relate totally with what people writes on forums like "Stuckinadoorway" and "Neuroticplanet" about this disorder. And I have also developed other themes on this "pure o ocd" thing + that I have some compulsory stuff that I've done since I was a kid, so I am sure that I have HOCD.

Although there is this one thing that disturbs me like hell (if I may say so), it's like this:
I have always been on the forums i mentioned above and searching for reassurance and often it made me feel good for a while until I found a new spike somewhere, it was always that way. But one day I told myself that I was going to do a real check to see if I had HOCD or if I was really turning gay so I tried imagining myself in a gay situation, just in my mind. And what do you think happened, I achieved an erection. This scared the .... out of me and I was in panic mode.

I told my parents about that and they just told me that a man can get an erection to all sorts of things that doesn't really mean anything. I got calmer and felt better for a while.
Until I a few hours or days later decided to do the real "test". I decided to check out gay porn with the thought in my mind that: "If i would get an erection I'm gay" and "if I'm just grossed out and no arousal" I'm still straight.

And I think you already can guess what happened, I got erected really fast by looking at it and I got so scared that I didn't know what to do.
Let's leave it there, I'm not feeling too good talking about it.

So my question to you is: could this be caused by the phenomena you described in the article "Can You Trust Your Johnson" from "yourbrainonporn"?

Because I have watched a lot of porn through the years, I started when I was like 11 maybe and are now 16 (if that matters?) And I watched it in periods where it was like once a day to sometimes twice or even three times a day. I moved on to wierder stuff like BDSM and ugh I hate this one: "Granny" sex. These things made me aroused because it felt so wierd and wrong and forbidden.

So now I'm wondering could the erection to gay porn have been due to my years of porn use and escalation to wierd stuff? I really hope that that is the case. The thing that is making me doubt is that I had developed HOCD before watching gay porn and it wasn't a direct escalation due to my porn addiction. So what I'm saying is that my HOCD was not gay porn induced, I had it before.

What do you guys think, did I only get the erection because it was disturbing to me and then released a lot of dopamine?

Please tell me it is like that, I'm really scared.

I tried watching it again on a later occasion and then I thought that I maybe only got the previous arousal because of fear so I tried being calm while watching it. And then I didn't get an erection, that felt good but then I got a bit anxious and then a groinal response and then an erection again.
So the erection/arousal didn't really come until I started to fear.

So what do you think about this? Is it due to porn addiction and "escalation"?
I really hope it hasn't anything to do with my sexuality? I just want to be straight as I've always been.

You'll have to excuse if my english could have been better, I'm not a native speaker.

And do you think a reboot can make this go away so I can be my old heterosexual self again?