Get a Clickfunnels Account, and build sales funnel around your main product, that way lets say with your current model you are making 10$/customer. With Clickfunnels you'll be able to get that Cart Value up and start getting 50-100$/customer.
That way you'll be able to increase your ROI (10x) without having to invest more into traffic or Ads.
And then Affiliate partner with others to boost your income.
After they bought your first product, send them some follow-up emails by selling your partners' product and receive a commission in between.