I can't remember the password for my iphone

I just changed my password last night that i knew that i would remember so i went to sleep and when i woke up i went to get my phone and do my password but my mind just went blank… I couldnt remember my password i know it ends with 7 but i have no clue what the other numbers are and i have so many things and data stored on my phone! Please tell me what to do! If it helps i have the 4 digit password and an iphone 5c

Basically you have two options:
Take it into the apple store and see if they can sort it out (ie reset your password)
OR
You may have to sync it with our itunes account, which wipes everything on your phone.