Exactly, I would recommend spending a few thousand on a good PPC marketing agency and let them set up your marketing. You might be amazed at what this would accomplish since your product seems fine.
This is exactly the moment I figured out this version is dead. At first I was thinking "ok I have a good product and now all I need are more folks in the top of funnel" but when all users chured out within 60-90 days... adding more marketing wasn't going to save it.