Iphone 4 on an endless restart loop, how do I fix it

I have jailbroken my iphone 4, and when my 3G stopped working I reset my network settings and my phone turned off and is now stuck on an endless loop, any advise? I tried hard resetting it, and there isn't enough time to do it…

1. Restart your iphone.
2. Connect it to your computer.
3.In itunes click on your device in the left hand column and then press restore.
4. If that doesn't work follow these instructions. Unplug your device).

Presumably your device won't turn on or off, so let's first make sure it's off. Just like in the reset section, hold down the home and power buttons until your device shuts off.
Hold down the home button.
While still holding the home button, connect your iDevice to your computer. (The computer you use to sync with iTunes.)
When you see a screen with a USB cable and a picture of the iTunes icon, you can let go of the home button.
Restore your iDevice with iTunes using the restore instructions in the previous section.
If this doesn't work then hopefully somebody else can help.

I would try to shut it off completely. If that doesn't work you need to connect to itunes and hit the restore button which means you will lose jailbreak privileges unless there's a jailbreak available for 6.1.3 on A4 devices.