Hahaha. I have had the same problem as you. I write, write, then edit, usually because I plan to post it up online somewhere for others to read.

What I find most helpful is finish the chapter(s)/"story"/meet your goal before you show it to anyone :/ The desire to show someone your work should overpower any obsessive compulsions to go back and edit xD;

I used to want to do this as a career, but then I had a sudden burst of desire to become a psychologist... Writing is still a very, very, strong passion for me, though.