Gmail woes

Hi all. First time back on the forums on a couple of years!

I come in search of advice. For a few months now (on & off) I've been receiving emails from companies in the US, someone somewhere keeps using my email address to sign up to in-store discounts and other stuff and I'm fed up chasing up each one trying to get the companies to stop sending me email! (and even when I do get one to stop I more often than not STILL continue to receive mail from them!)

It's gone beyond just selecting Spam and/or Phishing, I feel like my account is no longer, secure, in as much as I mean as secure as it can be in this day and age, so I'm contemplating making a completely new Google account but I'm not sure how, if at all, this will affect my current account, particularly with my Play Store account being linked to all the apps I've purchased/downloaded.

It seems like License transfer isn't possible with Google Play though from what I've seen so far.

Looking for advice/suggestions how best to manage this situation. Many thanks