I think there is a healthy amount of procrastination we need as individuals - it's our brain taking a break. Also there is a lot of stuff happening in our subconscious mind that we aren't aware of, and these "breaks" enable us to solve problems without really knowing it. How often have you had that "I get it now!" moment? Or when something finally clicked without you really having to do much?
There are people out there who don't procrastinate as much as others, but I think you'll find that you procrastinate as much as you need it.
Sure this is one type of procrastination, however there are other types which include not doing things because you're being lazy (this is hard to define if you need a break), or your attention span or concentration levels are just not there.
I used to procrastinate and I still do. If I wanted something so bad, I'd get it however it hasn't affected me to the point where I can't accomplish anything - I am just lazy.
EDIT: Also you have to think about your productivity levels for the hours you worked? Were you extremely productive?Perhaps you hit your limit? I guess overall, the important thing here is that you've recognised something you want to change and perhaps the actions you take will enable you to work more efficiently in the future.