How do you make a item consistently lose durability in your inventory

I'm trying to make a item that will lose one durability point a second. However, when I use the "deal 1 damage to item" block, it does one damage. I have it to run on a effect to do the damage consistently, but it does one damage and then stops. Also, if you can, could you tell me how to make a GUI fot that item to repair it on spot. Thanks