IPhone has a problem

So I have an iPhone 6 which I brought back in April 2016. There have been issues before with my phone deleting all my pictures, notes, messages, numbers, information and logging me out of apps. I got this fixed back in September 2017. Now this is not the problem anymore but a new problem has occurred.

I don't know how or why but some apps my iPhone 6 cuts of some of the screen which is SO ANNOYING. It makes the screen look like an iPhone 4. This started back in November 2017 and I can't take it anymore. When you look at my friends iPhone 6 their apps are completely normal and looks like, well how apps on iPhone 6 looks.

Please TAKE YOUR TIME TO READ AND IF YOU KNOW ANYTHING ABOUT APPLE PHONE THEN I NEED YOUR Help MORE THAN ANYTHING!

Carry out a full backup of your phone to iTunes on a host computer. Make sure that you select the option to backup your apps as well as that will make the later stages faster.

Then repeat the process but choose the option to backup to iCloud. That is less comprehensive but saves your most important data in case your iTunes backup file is damaged.

Next, go to Settings>General>Reset>Erase All Content and Settings.

If after doing that you still have the fault then you know it's a fault with the phone itself. If the fault is resolved then connect the phone to iTunes on your host computer and choose Restore Backup. If the fault returns then you know the fault is caused by some of your data, and it will likely be that one or more apps aren't playing nicely with others.

You can then try methodically deleting individual apps and then reinstalling them to see which app(s) are causing the fault.

A full backup does not include media you've ripped from CD. You must reload those yourself.

The apps may need updated? You should try searching on google.