How should I react to it? How do I deal with not being able to know? And how can I get over it permanently without relapsing? This isn't for reassurance purposes I generally would like to know from someone who's gotten over it or a professional.
I think you just have to keep doing the work, not engaging, and you'll focus more on other stuff in your life. It won't completely go away I don't think, I'm part way through the journey and I feel like if I wanted to I could dive right back into obsessing about the question at any point. But the therapy is helping me create distance from it. Instead I'm not giving it air time, and just trying to get on with my life. I have had a hard time accepting that the discomfort might always be there around this theme to some extent, the intense anxiety might return out of nowhere, it's never going to 100% disappear. In terms of using the word relapse I would say be kind to yourself, you're not back at square one, it sucks but you'll keep learning from it and ultimately be better in the long run.