big root problem. help plz!

[CNoe121#AC]

i just tried rooting my galaxy s2 sgh-i777 and realized it wasn't gonna work right since i had updated to version 2.3.6. Now i don't have wifi and i havent backed anything up. Is there any way i can still back everything up, keeping all my apps and info and unroot it? If so, could someone walk me through the process? It would be greatly appreciated.
Thanks