The feeling of dying inside will remain for a while and there is no quick fix for it. Thankfully it will subside as time passes.
Take a piece of paper and write down on it your reasons for loving him. Are they material reasons? Or do you like his personality? (which you just proved he has none).
You need to stop looking at all memoirs of you two together, pictures, emails etc. Do some work around the house or do anything else to keep your mind occupied all day. Get in touch with friends and plan something together.
Now that you have experience identifying an idiot, you will find another person who will be less of an idiot.