If you really want to be totally sure and at the same time have the peace of mind, probably just swap out the hard drive. For your past files to be as totally as unrecoverable as possible(I'm not even sure if there's such thing as 100% unrecoverable), as far as I know it's probably going to be quite complicated that you might as well just save yourself the time and change the hard drive.
Yeah I think paranoia would lead me into this conclusion eventually, NVMEs are not that expensive anymore these days so its not that big of a expense.