I'm working on coming up with investment thesis but I feel like I'm spinning my wheels. I'm taking a top-down approach, using IBIS, pitchbook, public into, and I have the financial criteria (growing industry, low capex, etc) but I haven't come up with a single hypotgesis in 1 week. Am I overthinking it?

What's your approach to developing an investment thesis?
How long does it take you to come up with one?
What resources do you use to test it?