CSS Forums - Unable to access my yahoo account

I am unable to access my yahoo account since 10 days..i had not signed in my yahoo account on laptop for many days but i frequently use my yahoo account on my mobile.Three or Four days back when i tried to use my yahoo account to check my inbox ,i could not sign in and message appears,"your username or password is incorrect"...And now whenevr i try to get access to my yahoo acount through laptop or computer,every time a box appears asking to answer the secret question which i have mentioned in my profile while making account.Now the problem is i am unable to remeber the anwer of my secret question nor do i know the alternate email adress ...Dear all memebers,especially admin and mods,kindly help me in getting out of this problem as my yahoo account contains my documnts and imporatnt data...One more thing,i have the same ID and password which i use to sign in at cssofurm(this forum) and also at facebook...i still can use both of these forums with the same email id and password but i can not get access to my yahoo account especially yahoo inbox...