Accidental "Login with Google" Triggers Blizzard of Spam

I have an ancient "trash" email address at Outlook (formerly Hotmail), that I use for shopping, email lists and any organizations/businesses I don't trust to keep my email address to themselves. I keep my "real" email address at Gmail protected, using it strictly for friends, work and the very few organizations/businesses I trust not to share or sell my email address. That system has worked fabulously forever. Until the following experience, I had years of literally zero spam emails at my Gmail address.

I was directed to Pinterest from some search results several weeks ago. My browser asked if I wanted to login using Facebook or Google (which has always annoyed me and turns out can be turned off- see below) and I accidentally clicked the 'Login with Google' option.

NEVER DO THAT.

When you choose the Google login option, it automatically gives that website your Gmail address (and your name and profile photo). Ever since then, I have been barraged with every type of spam in my inbox at Gmail. 

I actually had a Pinterest account that I could have logged in with that day, but nooooooooo... 

I deleted my Pinterest account. My next move will probably be deleting my Gmail account and starting a new personal email. Such a pain.

I deleted my Facebook account a while back, so I don't know how to remove prompts to log in using Facebook. To turn off suggestions to log in with Google:

1) Go to your Google account

2) Click on Security in the left sidebar

3) Under 'Signing in to Other Sites' click on 'Signing in with Google' 

4) Turn off 'Google Account sign-in Prompts'