wifi dosent works....

hello friends

I have made sum mistakes,
I leave in Israel, and I bought SM-G900A AT&T in the US and bring it to here,
it work good, but I couldn't change it to full Hebrew
only use morelocal2 and root to make him almost Hebrew
I alwise try to find a way to upgrade it to lulipop but its sims a bit of dengerus
yesterday, I made one more mistak....... and install an app " build.prop updater"
I thought by opening it I will be able to lern things
but just when I opend the wifi stop working, it alwise dark green, like it try to get turn on but unble to
I install some cheking apps and its look like stock
eventually I hard reset it to factory data.
and its still stock, also it works very very slow
and a lot of thing aint opening.

one more thing from the beginning, setting was a bit of problem
alwise fail down when getting in languase and the software update dosent open at all

byt the way my screen is also broken, and in Israel they say that the screen is not like in here so
I stok whit that too....

any idea.... some one ?!