Doctors definitely don't need your product, as they pointed out.
But consumers do!
I think you should have sold to consumers.
Having three doctors in my close family, I often found that whatever the tired doctor at the hospital is recommending is in contrast with what a doctor who care about my health (and is willing to look on their proprietary platforms) is recommending. That's why you ask different private doctors' opinions when things matter.
I found myself googling studies on what's the better treatment for $x and I would pay for better-than-a-doctor-advice backed by actual studies.
I think the problem, in your situation, is the scale of the operation.
If you want to do B2C, you often need investments and you can expect to become profitable in a few years.
Either find some funding or fix your cashflow.