I've had an unlocked 2.0 firmware iphone for awhile. and today hooked it up to my computer for the first time. I then proceeded to be an idiot and upgrade it when it asked (through itunes) and now its stuck in a screen of the usb hub pointing to the "iTunes" logo..... not sure what DFU mode is but that doesn't work. when i hold home/power it just loops back to the on position.. right now i'm getting error (20) when I try to shift+restore i've also gotten (6)

before it was telling me that I needed to get an activated SIM card.. i only have a t-mobile sim card. right now i've uninstalled 7.7 and installed 7.5 tried iliberty BS and winpwn... although I am a newb and have no idea what i'm doing. Is all hope lost?