You need some form of long-term aftercare.
I'm sure the rehab facilities you were in talked about that - quitting is one thing - staying off of them for good is quite another.
Find something that appeals to you - whether that's NA or AA, or a therapist or addictionologist - or even a pastor/rabbi - someone you can relate to and who can be there for you when you need them.
Good luck to you.
I have the exact same problem! I am currently taking up to 60 N+ daily and never manage to stay away from them more than a few days when I decide I will try and quit. For the moment I am just giving in to my addiction because I do not see a way, I am acutally suicidal without these pills. I totally underestimated them. The worst is the feeling when they wear off and leave you with that feeling of dread. But you already took a big step cutting down to 15, I would not manage it. I do manage to not take them the days I work because I do physically exhausting work and this wouldn't be possible with the pills.So that is one way, keep yourself absolutely busy and concentrate just on that day. When I have a pillfree day I really just take that day and don't tell myself I will never take them again because I am just not at that point to give up yet and just the thought of having to live without them sends me straight rushing to the chemist before work. But with the thought "just today" I manage to have a few drugfree days a week telling myself if it gets really bad I can still take them but I am okay for today...this is by no means an ideal situation and of course you should get real help and aim to get off these pills, but do not go into the thinking what every withdrawing addict fears: How to get through LIFE without it. Just get through the day and reward yourself whenever you have achieved a step, for example cut down to 10 pills etc.
These are just my thoughts don't forget in the end I am just like you and acutally not in the position of giving you advice just letting you know you are not alone there so many people are hooked to these horrible pills..
Cutting down to 15 is huge. Try to cut down even further and get into some type of aftercare. NA would be a good start. What makes you go back to the pills? Have you figured out what your trigures are?
It's never too late to quit this horrible pills!!!!
Here's a list of foods good for the kidneys
http://www.mybodywisdom.net/pdf/Nutrition_for_Kidney_Yin.pdf
Cutting down to 15 is huge!
Best of Luck
not to sound stupid but what is N+ ???