Automatically saving Emails

Hey there, my Gmail accounts have been hacked and as a result they got alot of my accounts and permanently deleted the emails that have been used to reset my password so I don’t know when I’ve been hacked
(I already changed the passwords to 24+ characters with symbols and everything but it seems like they have put maleware on my pc or smartphone and are able to get them)
What I’m asking here now is, is there a way for me to save all emails so that I can see them even tho they got deleted on my gmail account?

I think what you may be interested in is discussed (more or less) here: