Ask HN: How to prevent losing confidence in the idea few days after starting up Posted by throwawaybagbag on Tuesday May 23, 2017 @09:44AM from the ask-hn dept. ( 3 comments | 2 points | on HN )
Also, if you don't feel that strongly about something a few days later then I doubt you should work on it.
Don't get me wrong I've got many ideas I went out found the perfect domain name and then it died.
I think the best thing to do is create a landing page and/or talk with some potential users.
If you don't have evidence or research, start on that first.