Oh, I've been exactly where you are. That gut-punch feeling when campaigns just spiral. It's not you - the platform does this to all of us.
A few things that helped me when I was stuck in that loop:
First, pause broad match for now. Go phrase and exact, high intent keywords only. Broad match without clean conversion data is basically setting money on fire.
Second - and I cannot stress this enough - get proper call tracking in place. Not just extensions, actual tracking with a duration threshold (60-90 seconds). Without that signal, you're guessing, not optimising.
Third, dive into your search term report. I'm betting that's where the real bleed is. Fourth, for Campaign 3, duplicate a working campaign and just swap the geo. Way fewer hidden settings to mess up.
And whatever you do, ignore Google's own recommendations until you've got decent data flowing. Their advice only works once the account has history. Not on a fresh, messy local setup.
Your bidding isn't the core problem. It's the data pipeline. Fix that first.