Why is it that sometimes, my intrusive thoughts feel “calm”, “good” or even “right”?

Sometimes I would have the most horrific intrusive thoughts, but while having those thoughts, I would feel a huge wave of calm.

Like today I thought to myself “what if I was meant to have [insert disease here]” as I was reading about said disease, and for some reason, it felt right in my gut! I do not have that disease; it was an intrusive thought about my future.

I had tried to think some opposite thoughts, and I had been improving the way I interpret intrusive thoughts, but I don’t know why I had that feeling at the moment? Now when I look back on it, sometimes I still wonder if it’s “meant to happen” in an “it feels right” kind of way.

Or maybe the way my nervous system is handling intrusive thoughts is getting better and my mind (old programming) simply hasn’t caught up yet? Idk this just feels very weird, and like a dissonance