After private browsing I have been inundated with spam
I visited some questionable websites in private browsing mode. Since then I have been receiving a large number of spam email. It seems private browsing is not private.
Did you enter your email address in any websites?
Private browsing mode is only meant to keep your browsing private from other people on your computer. It doesn't save a history of where you went. That's it.
I'd suggest downloading www.malwarebytes.com and scanning your computer to ensure you have no viruses.