Wifi issues

[Android Question]

I have a Samsung Galaxy y, and i have been using my home wifi with no promlems for months, then i had to disconnect for a day and when i tried to get onto the wifi the next day it wouldnt work. it connects to every other network with no issues but when i try to conect to my home wifi, i type in the password correctly and then i says "authenticating" then comes up with the box to type my password in again, and it repeats what happened again and again.
I've tried;
-turning wifi on and off
-turning phone on and off
-turning the wifi box in my house on and off
-typing *#*#526#*#* in the keypad and waiting
-pressing 'forget' then re-connecting

please help!