You both sound like me when it comes to overthinking things. It's one of the reasons why most of my stories never get finished. Though, recently I finished a draft for a short story a friend of mine challenged me to do. She told me to write a short story draft with a minimum of 5,000 words, about a Medium who meets a spirit that tells them about their last day alive. I had a week to do it.
If I gave up, my penalty was no games for a week. If I did it? I'd get a reward.
I was allowed to ask for help with ideas if I got stuck on a scene. I only asked for help with an idea for the spirit's death scene, because I couldn't settle on an idea myself.
In the end, I finished draft in 6 days with a word count of 6, 500ish words.