How to downgrade my iphone from ios 7 to 6.1.3

Will i lose my stuff but i backed up please answer i'm scared

Yes, you can downgrade. To do this:

Download iOS 6.1.3 firmware file for your iPhone (Google it)

Plug you phone into iTunes

Put it into DFU mode and wait for iTunes to recognize it in recovery.

Click "Restore" and shift (PC) or option (Mac) on your keyboard

Select the iOS 6.1.3 firmware file

Wait for iTunes to restore to the 6.1.3 firmware

Note: Once you restore to iOS 6.1.3, do not restore from an iOS 7 back up. This will cause compatibility problems.

If you backed up while on iOS 7, you can't use that backup on iOS 6.

Also, make sure your phone is in DFU when you try to restore. Otherwise your phone may be stuck in recovery mode and will have to return to apple for warranty. I would know, just happened to me.