I bought an iPhone 3G unlocked by jailbroken yesterday, this morning I opened the Cydia app, and as soon as I opened the app, my mobile network was gone and would not come back. Cydia told me to reboot my iPhone so I did this, and the Cydia app was gone. And my phone turned off, if I try to turn on my phone it tells me to connect it to iTunes, so I did that this morning, iTunes tells me to reset my phone, but that won't work since it is jailbroken.. Can I jailbreak it myself and unlock again?