I'm in a similar situation myself and in the process of figuring out why. I would recommend reading the book "Traction" by Gabriel Weinberg.
I think it is relevant for you to share your project - there could be many different factors why traffic isn't converting. Trial users from a Show HN are great but I've multiple websites that had traffic but 0 converted. This tells me that the traffic audience may not be my target customers.
I'm doing things that don't scale now .. so actually going out to acquire users manually. What I've found is that the value proposition might actually be a better fit for folks outside of the HN community.