Info 2 [q] need immediate help sch r530u!!!!

Hello everyone new and I just really found out about xda and have a major problem ok I have us cellular sch r530u s3 and I rooted then I unrooted to get kitkat update...so once I unrooted I lost root but rooted Alps that I use are still usable like root explorer and adaway and when I try to get ota it says sorry device modified so I went and got root checker and it says device doesnt have root access..so I went and got odin 3.07 and flashed some kind of recovery called cf autoroot d2usc schr530u tar well anyway now I cannot boot into any recovery and when I try to the samsung logo comes up but it turns red then screen fades to black and nothing happens....so as of right now I am begging for help to unroot fully and restore stock recovery and be able to ota kitkat...also I've been trying to find the firmware official for this model and no luck I dont know what is wrong but im so stressed trying to figure it out...someone please help!!! Greatly appreciated!!!! Thanks!!!!