What are your troubles to find Product/Market fit?

Would love to share some of your pains. Personally, I've started a company holding the tech role (I don't like calling myself CTO, because the CTO hat is just soooo huge), Ive always tried to ensure we use 'tech to empower the business'. But how? When the numbers doesn't seem to move?

"Data driven" decisions to build a company - But how? What data is important to measure other than sales (worse when back to the first point, numbers are not moving).

What are/were your pain and thought process trying to find your own Product/Market fit?