Actually, psychologists proved that this is actually a character trait that provokes such last-minute behavior due to the adrenaline rush and so etc.
The thing that helped me to deal with this problem is task management.
It means breaking one task into several chunks and tackling them one at a time.
I also use timer and start with at least 30 minutes. It takes a lot of will power to actually shut off all distractions, open the necessary docs, have the tea/coffee ready and start focusing on one task.
But the results are rewarding, since you have a chance to review your work one more time before turning it in and eventually you eliminate the stress level that occurs when you put everything off till the last minute.
Try these things, maybe they will help you.