Inappropriate email senders?

Creating a new email address (a completely new one, not just an alias/secondary account) is the only way to actually stop these spams. Presuming this is an iCloud account, I don't know what process you've tried to change your email address, but perhaps this will help:

Change your Apple Account primary email address - Apple Support

Absent that, you can get a third-party spam filter that would be more effective, most likely, than the spam filter included with iCloud (or any other email provider). I've used SpamSieve for years and have been quite happy with it, though I still have had to change email accounts on a couple of occasions when one of my accounts got into broadly-distributed spam lists. Any such filter on your computer, though, does not block the emails, just does a better job of marking them and sending them to the Bin.

For the future, you may want to look into getting an iCloud+ account so you can use Hide My Email with any site, company or service that you can't completely trust. You can get an iCloud+ account for as little as 99 cents (US) per month. Then if any of those "temporary" addresses gets onto a spam list, you can just deactivate it and not have to mess with your actual account.

Regards.

iCloud+ won't do anything for your existing email address being on spam lists. It will only help you avoid getting on such lists in the future.

There are no free anti-spam filters available that I know of (if any exist at all); at least none that are better than what iCloud itself provides. You'll need to change your email account, then work to avoid getting on more spam lists in the future. Liberal use of the "Hide My Email" feature of iCloud+ is highly recommended.

Regards.

I believe that if you remove that email address as an alternate, you will then be able to add it as your primary. But not having encountered that personally, I'm not certain. Someone else here may be able to confirm, or you can call Apple Support and they can probably walk you through the process.

BTW, it's a bad idea to post your email address or any other personal information in these forums. These are read world-wide and posting an address may well just get you onto yet more spam lists. I've asked the Hosts to obscure your address.

Regards.