iPhone 3G problem! Need help fast please!

I will tell you whole story now, and it will be long. A year or more ago i bought an iPhone 4 for a lot of money and after a month i smashed it(not on purpose) and repair was to expensive so i sold it for little money. Then i was using ordinary phones untill a week ago. I ran on cheap iPhone 3g and i bought it. It was on stock firmware 4.2.1 i jailbroke it. Everything was doing just great i was playing games and using apps, but almost every game and/or needed newer firmware version, so i started looking for newer iOs, and iPhone 3g couldn't take newer iOses. After day or two i ran into Whited00r 5.2.1 firmware for iPhone 3g
and without any thinking i installed it. I went to see version and it said 3.1.3 i went nuts because i wanted newer apps so i tried to put back iOs 4.2.1 and error, tried again and error again then it went to recovery mode o i tried it restore with itunes but nothing, all i got was error 1601 or 1602, i watched videos how to exit recovery mode by home button + sleep button but nothing, i tried it with redsn0w but whenever i put it in DFU mode and go to recovery fix it says usb communication problem on 3 different computers, then i tried restore it with same whited00r firmware but that didn't work and i was getting error 1015 and i fixed it with iReb, nothing works please help to get out of recovery mode it doesn't matter on what firmware just that i can ue my phone. I would like to go to 4.2.1 but if it int doable no problem.
Thanks ahead!! sorry for bad english and long story.