Having a healthy relationship takes practice. I'm imagining you both need to work on boundaries, but only you can control your own actions. As in, if I were in your shoes, the first thing I would do is pick apart what is my business and what isn't. Because what you have described is not healthy.
A "normal" or healthy relationship would look more like this: You would have a friend who learned to trust you over time, and who eventually felt open enough with you to open up about a shared experience with you, a porn addiction.
I'm honestly not sure why this is important to your question, as you go from "she told me this" to "i am battling my triggers towards her," and these sentences don't seem related to me. They seem like two different topics that you have accidentally confused as cause and effect in your head.
But for the sake for it, if you had a healthy relationship with your friend, then you would have clearer boundaries about what to do if one is triggered. For instance, with one of my best friends, he knows that if I accidentally trigger his PTSD, that he can tell me to stop talking. And he knows he can trust me to either change the subject or let him be alone for a while, or whatever he needs. In turn, I know that if I told him he was triggering me, he would stop. End of story.
At the same time, we do not feel entitled to each other's behavior. If he were to start hanging out with a special someone, and I found myself worried that he was going to abandon me, I would never say "you are triggering me, and that's unfair." I would say to MYSELF, "wow, I'm having a strong reaction to my friend's choices. I should work on these feelings in my own time."
I can't see your entire friendship as I don't know either of you, but I would wager that this friendship has become toxic for both of you. If that's the case, you will both have to decide if you want to keep the friendship, and, if so, how you will work on these issues so that they stop interfering with your relationship.
This is unfortunately something you have to do on your own, for the most part. That is, you will need to work on your own triggers, one at a time, and determine if they are your business or not, or if you have some mental work to do.
I would highly recommend therapy for you. With this type of issue, it wouldn't surprise me if you have other symptoms that an official diagnosis would shine a light on. Borderline personality disorder, for example, comes with an intense fear of abandonment, and sufferers who have gotten the diagnosis have been able to go through similar treatments as others with the disorder to learn how to make and maintain healthy relationships with friends. The feelings are intense and real, and people with them have to work harder than others to deal with them. But over time, with practice (around 18 months of practice), the brain will rewire itself and it will become easier and easier and easier to have those healthier boundaries.
I hope this helps.
My step one, in your shoes, would be to allow my friend to avoid me when I am acting triggered. Or, to know how to step away so I don't take out my emotions on my friend unreasonably.
After all, emotions are not facts.
Welcome to the forums, by the way :)