How do you ramp quickly and effectively when selling in a new industry?

Was an AE at my last company selling to HR. Just started a new closing role at a pretty huge SaaS company selling a completely new product to and completely new buyer persona.

Today was, I’ll admit, overwhelming. I feel like a complete moron.

I know it’s a natural feeling, but it still sucks.

How do you guys ramp up quickly, learn something foreign product , and play politics, while not burning out?