Can changing my iPhone's IP address prevent further hacking attempts?

No. If they know your email address or your phone number, which they clearly know, changing your IP address won't protect you. And you haven't been hacked, nor can you be hacked unless you respond to those scam email and texts, which is exactly what they are hoping you'll do. Just delete the phishing and scare scams. Block them. Never respond to them. It's the bane of our existence these days. The scammers become more persistent. But we have the ability to simply ignore them, block them and not let them get the payday they're hoping we're dumb enough to provide them.

See this --> Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support

Your phone can't be 'hacked' unless you jailbroke it.

Your phones IP address changes all the time.

Secure your accounts with strong passwords and 2 factor authentication.

"Can changing my iPhone's IP address prevent further hacking attempts?: If I change my iPhone IP address will that help with e-mails I’ve been hacked and payments missed someone trying to login to my accounts by using password to many times "

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Resetting to Factory Settings:

No. You have no hacked iPhone. If -you are so concerned, then reset your iPhone to factory settings, as if you were to sell it. Go here: What to do Before you Sell, Give Away, or Trade in your iPhone, iPad, or iPod touch - Apple Support. Perform as instructed there, including the backup creation and iCloud log out. Take a few screenshots --one of each home screen, to know what was placed where, prior to this reset.

Changing the IP Address:

If you are not using DHCP, but rather are using a static IP address, then you might lose connection to the network all together, and that would not help with receiving eMails, but your could read them on your Mail app, if you have the eMails downloaded.