My message icon is gone how can I get it back on my phone

icons don’t “disappear”, and the Messages app is not one that can be deleted. You either moved it to another page of the Home screen, moved it to a folder, or removed it from the Home screen. So search for it using the Search function. If it is in a folder the folder name will appear next to it. Alternatively, assuming you have iOS 13 or later, go to the App Library (the last page of the Home screen) and drag it back to any other location on your Home screen pages.

Great, glad it’s resolved. And issue like this are one reason there is user to user Apple Support Communities.