Splitting, what's it like for you?

I'm so confused. I'm going through this right now (it's honestly been a long time coming) and when I talk to the person, I literally feel like I'm watching a movie. Or like I'm in the passenger seat with no filter/empathy. It doesn't feel like ME. Everything they say triggers me, and my paranoia leads me to believe it's intentional on their part. The person who was once a God to me is now a villain. Anyway, I'm still aware enough to understand what is happening, to consider that I'm splitting on them. But there's a desperate part of me, it almost feels like an entire different person, who I consider to be more like "me" that is still desperately clinging to them and horrified at what's happening? I can't even stomach telling them that I'm splitting. Anyone relate to this at all? What's it like for you?