TL;DR:
Do you even slightly think your sexual attraction to animals is your fault?
I don't believe so.
I've had a deep love for animals, especially canines, for as long as I can remember, far predating sexual desire. I never felt right around other people, like I couldn't relate to them and they couldn't relate to me; they were uncomfortable. Animals, on the other hand, I felt like I understood them and they understood me in a way my peers couldn't. My sexual attraction to them happened naturally, I loved animals and when I had those interests I just looked for animals "doing it", it felt logical to me. I think the first "pornographic" thing I ever watched as a video of wolves mating on YouTube, and I was enthralled by it, I thought it was beautiful. Needless to say, my earliest sexual thoughts involved animals, and I imagined myself as an animal as well.
I'm a therian and I'm not entirely positive if there is a correlation between the therianthropy and zoophilia. I'm not entirely convinced there is, as while canines are my primary attraction (and I have a pretty significant bias towards my theriotype), I'm sexually attracted to just about every kind of animal under the sun to be honest.
I think it can be a mixture of factors. I believe at our core we are hard-wired into certain predispositions, and the events you experience in your life shape how those come to fruition. To phrase it more eloquently, I believe we are born with our immutable characteristics or tendencies, and the way in which those manifest and grow is subject to your lived experience.
I'm not zoo-exclusive, I do experience some sexual attraction to humans, though that developed a few years after my sexual attraction to animals began. I'm somewhere between homosexual/demisexual. On the flip side, I'm sexually attracted to male/female animals equally.
I can't explain why I'm not straight. I can't explain why I'm zoo. I can't explain why my zoo preferences do not align with my human preferences, this is just how I've always been, no matter how hard I tried to change it. And believe me, I tried
incredibly hard in my early years to change my sexuality, both in regards to humans and animals.
I have thought about journaling, but I'm too afraid that my family will find it, so I can't.
You could download a journaling app on your phone or computer, or even just use a note taking app if that would help. There is a certain grounding/calming ritual in the act of writing on paper that gets lost that way, but it achieves the same thing in the end. Or you could have a physical journal for certain topics and a digital journal for more private ones.
I don't journal often, but I find that having a space where I can type out all of my word vomit is nice (especially since I type really fast and my brain goes at 10 million mph), where I can save a physical journal for more composed/focused writings.
Let me make one thing clear, just in case anyone's a little confused: I'm not ashamed or disgusted (most of the time) about these sexual feelings I have towards bottlenose dolphins, and I'm absolutely not saying anyone should. All I'm saying is that I (me, independently) feel personally responsible for the mental implementation of my zoophilia, regardless of if I had control over how my brain developed it. This also includes anything related to it, such as betrayal of trust, exploitation, and ridicule/scorning.
Like I mentioned above, I would consider "true" zoophilia to be an immutable characteristic of sexuality, like a seed that grows based on your experiences in your formative years. I don't think it's unreasonable to imagine that, hypothetically, while you have that predisposition, it was your ASD that led to a special fixation on bottlenose dolphins, which led to your attraction manifesting that way. I don't think it's "your fault" you have that attraction, because it was a series of innocuous events combined with circumstances out of your control that brewed the "perfect storm". But I believe at that point it's down to the rigidity in which we are defining "fault".
I'm just some random asshole on the internet so take my psychoanalysis with a grain of salt. It's not particularly scientifically based on anything and rather just my own musings, but I hope it's interesting at the very least.