After HOURS of trying to fix my phone I restored to backing my phone up in iTunes
Step 1 plug iPhone into computer
You will have to unlock you phone and it will ask you if you trust your computer/laptop obviously click trust!
2. Go to FILE> DEVICES > sync iPhone/iPad
3. Transfer purchases from 'iPhone'
Wait till that's done
4. Then click BACK UP
Wait till that's done.
Unplug your phone
5. Go to Settings > General> scroll to the bottom > Reset > Erase all content and settings.
Two signs will appear asking whether you want to erase your iPhone click Erase, twice.
Your phone will restart, go through all the normal settings at the beginning such as language and country.
It will ask you a few settings down how you want to restore your iPhone ( I found iTunes more reliable)
( you also have the option of restoring from iCloud, it's up to you)
6. Plug in iPhone
7. On your iTunes it will ask you if you want to restore it from earlier, click that.
This will take about 15 minutes hopefully
Keep your iPhone plugged in when it has been restored and iTunes will sync your phone and you'll get all your apps back!
That's how I managed to get everything to work, sorry for the detailed description it's incase someone doesn't know how! Hope this works for everyone <3