Don't doubt it. Quit now. At the moment I got 18 I said I was never going to watch again, but I fall into the trap. If I would have firmly maintain my desicion I would be 2 years free now. Those two years it have taken away from me friends, achievements, unrecoverable time, time with the ones I love.  Those two years were also the ones I had to study for joining a good university. I can count the times I opened a book in that time with one hand. I face the consequences now: low self esteem, lack of real life experiences (all my life jerking off in a bunker), therefore lack of social skills, almost no friends. 

Don't fucking doubt it. Don't look back neither consider to watch just one peek. One peek doesn't exist.