forever delete gmail items that flowed into mail?

I have two email accounts . . . @mac.com & @gmail.com, with both being available in "Mail".

Question: in "MAIL" how can I permanently get rid of thousands of gmail items that now reside in my archive?

Not sure if this is really happening, but when I delete them, gmail (viewed from their own site), seems to go into overdrive to restore them.

If that's possible - how can I keep that from happening?

btw - Gmail is keenly trying to keep their items from being deleted . . . they want to keep every bit of info on their users.

Regretting that I ever signed up for gmail, I develop a plan to omit it from my life, but for the moment I must keep it open.