Remove Yahoo from Chrome by fixing your search settings first. Then delete weird extensions.

SimpleLogin is usually the best first step for anonymous email, while Proton Mail and Tuta are better as private inboxes behind it. Proton says it serves more than 100 million accounts, which makes it the biggest name here [source: Proton].

Use private browsing for quick cleanup, not true invisibility. Chrome calls it Incognito Mode.