Before every email as yourself "if this email went public, would anyone care?" If I ever answer "yes", I don't send it. I either call or meet in person assuming we're not too remote.

You're doubling your surface for anything unethical, too. It not just the NSA, so it really makes no sense to take additional risk in this regards. You are adding an [or] operator, one that can lead to a complete failure mode. This is the opposite of risk diversification. Unless I'm missing something.

Yes, Google has your email, but not your credentials. A breach of your email exposes all the email you have now. Bad, yes. A breach of your credentials exposes all the email you get until you change them, and if you don't know to change them...

Ditch Gmail and host your own email server.