Just starting with something random is a good idea. I think that's usually also how I get out of these situations.

I actually recently had the same issue when looking for a mouse. I wanted something lightweight, works with bluetooth for day to day work, but can also be used wired (with less latency). But it had to be with usb-c.

This was surprisingly hard to find and it took me several weeks before I decided. (Got the Keychron M3, which really fits my needs perfectly) Unfortunately this reinforces my behavior to keep researching for a long time before deciding. (honestly the time I spent on this was probably not worth it, even though it is a good mouse. I would probably have been fine using my old logitech for a while longer)

Sometimes there is not even an option that fulfills all criteria, and in those situations I can keep looking forever. Then it becomes really important to just let it go and get something that's "good enough".

Not sure how to train myself to do more of the opposite though.

You might be right that it has to do with my current mental state too. I recently moved to a different country, and (even just sensory wise) it has been an overwhelming week.

When overwhelmed, my mind tends to go blank and I just keep researching forever in some kind of zombie mode. I wish I knew a way to ease myself. But that is actually one of my main challenges, how to rest and recover. I tend to default to browsing/researching more online whenever I have nothing to do, or when I'm too tired.