Overthinking issues?

So I was on YouTube and I was watching some videos and one video had a quote “fall into a sleep like death” now I remember this quote and I cannot stop thinking about it. Is this overthinking? I’m perfectly healthy nothing is wrong in my health except overthinking. The reason I have overthinking issues recently I was overthinking about some incidents and I told my mom about the incidents and she said it’s ok and I should not worry about. So this incident an example of overthinking. And I shouldn’t be worried about it and I am safe? I knows is incident is nothing to worry about but my overthinking issues thinks it is so do you guys have any advice for to get over my overthinking issues?