How Dificult would be to change your e–mail address you have for years and transfer the safe e-mails to the newone?

Hello:

For quite a while I have been bombarded with nasty, phishing scam and the like. I am retired and old and do not want to see those e-mails from Viagra adds, insurance scams, real estate scams, even like today from some loose woman wanting this and that. I do not know how these people got a hold of my e-mail account. I have a son with my same name but his e-mail address is different than mine. So I have used the block e-mail addresses to create a rule at no avail. These scam artist use a different e-mail addresses so that does not work. If I change my e-mail address, how difficult is that and how can I save the good emails I want to keep? Thank you all.