I am receiving spam emails from my own email address

Yeah, I get those. Most of us do. Message-handling rules can usually filter this specific spam fairly effectively, if either the mail server provides rules capabilities, or particularly if you have a Mac (or other computer) that can filter for you. Anything arriving both from me and to me (and I usually check a few other SMTP headers) gets marked as spam, or gets deleted.

You will likely want to change your email address and not give it out to websites that sell it for income. You can use the Hide My Mail service provided with iCloud+ to give out email addresses to websites that can be easily managed. Once another company has your email address, they can constantly send you Spam emails and the originating address can be a fake address and even appear to be your own. It does not mean your email has been hacked, it just means that your email address that you provided to a website was sold to a spammer.

It's called spoofing. The sender can put any address they want into the sender field, even though that's not where it came from.

There isn't really anything you can do about it since blocking the "sender" will prevent you from getting any emails.

Eventually, they'll stop as the crooks will move on to a different address to spoof.