think of your goal - tis the only cure for procrasination imo. get it done and then give yourself a treat for completing it on your own imposed target. schedule your time on a 3 day basis to work around the surf forecasts if you must and dont forget to schedule 'effective downtime' - thats proper relaxation to you and me..NOT procrasination which isnt really relaxing.
as for the parent thing - at least they take an interest in your life and offer you guidance, be thankful for that - it is done purely out of love.
To get them off your back - sit down and listen to what they have to say, ensure you consider their opinions - to get power in the relationship you have to prove you're worthy of it! then explain that because they raised you so well (compliment them!) you are well equipped to be able to make your own decisions and accept and work through whatever consequences life may throw at you. reassure them that you do listen and their opinion will always be of value to you.
If that fails - slam some doors and turn your music up really loud