Strategies for Generating Sales from Cold Databases in Startups

Hello everyone! I am a BDR-SDR at an early stage start-up offering offshoring/outsourcing service to managed IT providers and accounting business leaders (top 2 ICP). I am a single person building & driving sales for the company without any marketing team for building any brand awareness, mass reach or generating inquiries. I am solely working with cold database from tools like ZoomInfo & have A/B tested different cadences with different email copies & sequences. Open rate is pretty much between 45-60% however not a single prospect or a conversation anywhere. I generated a couple of suspects thru cold calling but again after sending them details on email - radio silence. Looking for help or guidance on how to go on from here to generating demand & get sales, when strictly limited to cold database.