Is this normal thoughts or some kind of illness that makes me think so much?

This takes aways all my motivation on daily life and not feel like doing them, and if I do, IL be like "no I'm not gonna do it, let me think about the thought just to see if it is pain" the thought is surgery, anesthesia needles and stuff like that.

Everyone I think about it, IL be like this is my last time, so let me take my time and think... but it isn't really my last time. Thinking about how they shoot you with the needle and how it looks and prepere (anesthesia needles only), and how they use the knife in surgery. be honest, this question may get removed if I use this word that starts with the letter d and ends with th. .. (5 letter) what's the point of going on and on if you can't empty your mind and be positive, I take whatever negative or medical and just stuff it in my mind forever.. how do people live so wonderful and a great life and going out, taking picture, posts etc.. 😟
Is this normal thoughts or some kind of illness that makes me think so much?
Post Opinion