Frozen phone

While it’s called an iPhone it isn’t really a phone. It’s a very powerful pocket-sized computer that can also make phone calls. And like any computer it needs to be rebooted periodically. To prevent it from happening again turn it off and on again occasionally (once a week, perhaps). See these instructions from Apple—>Restart your iPhone - Apple Support

I had the phone screen becoming unresponsive to any touch multiple times just today! I have tried what you suggested but it’s not been of great help now!

what does that mean, my phone is a year old! And I’m a Very heavy user, what do I do to ensure it doesn’t happen again?

Quickly press and release the volume up button, then quickly press and release the volume down button, then hold the side button until you see the Apple logo on the screen

You’re welcome.