How do you know when your product is a failure?

I sell one product on Amazon currently as a Private Label seller. My question is how again, how do I know when to call it?

My product does about 11 units sales on average a day. The leader in my niche does 100+ a day. I have the best unit in my category. My unit is the best. I think my listing images aren’t really showing that so I’m going to redo them again (for the 3rd time) but this time im just making them less busy and easier to understand. There is so much better about my product that I am trying to show it all but its too much. (Even though my designer is going to kill me with revision pricing which is bull shit).

Anyway, im still getting sales and im number 10 in rank atm. Ive spent so much money on ads when i first started last christmas. I didnt really know what I was doing and was pumping loads of money into my listing on ppc while having pretty crappy photos. I pay out $500 a lot in ppc and its killing my Credit card. I get money every two weeks from my sales but it doesnt cover what was taken in ad spend. I have lowered my ppc and raised my prices and i still get sales but I think in still not making money im actually losing a bit of money each day. I think..

Im not really sure the best way to calculate if im profitable or not tbh. Know i should know that but im being honest.

I was going to try and pay for a video and fix my listing images and see what that does as a last dirch effort. Problem is I only have around 500 more and since i dont really make enough for the next batch i didnt want to get more but I guess I could use the money I have gotten from sales as a last time go.

Thank you anyone that can offer any guidance. I dont have anyone I know who sells on Amazon and I didnt pay for a course ( allthought im starting to think i should have)