I was thinking about first trying to quit P*** for 90 days, and after I have achieved this working on the next big step - quitting m*****bation. Is this a good idea? Or is it better to try going all or nothing?

Neshamatehorah,

    I have a question.  Do you really want to stop?  And, what is it that you are wishing to stop?

    Our addictive disease is an addiction to Lust. The acting out, i.e. porn and master... is not the problem. The problem is the lusting which leads to the porn and masterb...
    As long as you are doing either of the two, you are lusting in a very big way. And, as long as you are lusting, you will not be able to stop acting out in other ways.
    I personally am powerless over lust. I cannot lust even a little without eventually acting out.

  Are you only afraid to give it all up? Don't be. Many many people have "given it all up", and then went back to lusting again. It sounds to me perhaps that you are having difficulty with the "90 day" idea.....such a long time! BUT, I would advise you to look at only 1 day, and one day alone. There is only today. If you really are sure that you do want to stop, then top "just for today". Tomorrow does not even exist. Just for today and one day at a time.