Desperately need help with lead generation

My business is experiencing a pretty rough time. We're a B2B SaaS provider of automation solutions for small enterprises. Over the last few months, we've been losing MRR quickly due to high monthly churn.

There are two issues:

  1. Churn: We're losing our current clients due to (what I believe to be) a significant discrepancy between how our leads understand our service and what we deliver.
  2. Lead generation: Our lead gen tactics, like Google Ads and outbound email campaigns, no longer yield the same ROI. We're paying a lot for ads, and our organic channels have plateaued. Basically, our lead quality has plummeted.

Our team is small but competent and operates on a minimal monthly budget. Does anyone know how to improve our situation, or has anyone been in a similar spot?

Please let me know what you found effective in finding amazing leads.

Edit: Thanks for all the help, folks! I tried Wiza's free trial, and it's decent if you just need a handful of emails to test out. It pulls verified emails from LinkedIn Sales Navigator but the free credits run out fast.