I'm trying to find startup ideas first, not to verify if my startup idea is worth. And I wouldn't verify it in such a way. I have read books already on the subject and this seems like a bad idea.
All of that said, this topic has been beat. to. death. here on HN. Use the search box and you'll find more discussion of generating startup ideas than you can shake a stick at.
"Ask HN: Looking for side project ideas" https://news.ycombinator.com/item?id=23290536
"Ask HN: Idea Sunday" https://news.ycombinator.com/item?id=7693262
and a couple "what would you pay $X for" threads https://hn.algolia.com/?q=ask+what+would+you+pay