You cannot change your primary number from the desktop client alone. And because I had no active phone session, I was soft-locked into (now)someone else's phone number. The only 'solution' was to message the random guy, explain and ask him to forward the login verification text message they sent him.

Afterwards I just deleted the account outright myself. anything that desktop-hostile isn't worth my time.

The obvious question is "why not just have a backup logged in phone session to solve this" and the obvious answer is because I don't fucking want it on a phone. And I'm not paying ~50 a year for a burner phone just for telegram.