First, before you consider doing a hard reset, make sure your backups are running properly. Go to settings and find your backup,and make sure everything is backing up properly...I'm sorry, my phone is on W10m, so I don't have the exact steps.
Once you do restore, when you hard reset the phone, you'll sign in with your Microsoft account, and you will have the option to restore your phone. If you do, it should push all of the apps that you had installed, restore your tile positions, restore your email accounts, and your text messages.
I had done this to my phone many times as I went through the various test builds, or set up my phone again. It works very well. Things like text messages restore reliably, and the apps will all restore, although it sometimes takes a while.
The things you will lose, is any progress in almost all of your games. All of your pictures, documents, songs, podcasts, audiobooks, or other media will be deleted from your phone. It is aggravating, but Microsoft doesn't maintain any of your podcasts, so you'll have to re-add them individually.
Your pictures that were stored on your phone will be gone, but if you had them backing up properly to OneDrive, you'll still have access to them in the Pictures hub. The same for documents.
Songs are one area where you'll have to copy them back into your phone manually.