The only way to really do it is to wear non stop 24/7 and you also can never hold it it. Every time you hold it in your tighteing your muscles. As soon as you feel the urge you must relieve yourself right then and there. It will take a lot of time and you may never be able to lose control at night since you can't force yourself to go while your sleeping.
The power of the mind is really strong. Telling yourself constantly outloud that you have no control can actually assit you. Have your husband join in on this. It's like when you tell a lie so many times you actually start to believe it's true. You need to forget that your trying to lose control and tell yourself that you already lost all control.
You can also try hypnosis cds. They are an extension on what I just said. It's basically just an additional voice telling you again that you have no control. You can't depend on them to do the trick for you alone, use this only to assist you in telling yourself that your fully dependant on diapers.
It will also help to wet yourself while not in diapers. If you only pee in diapers your mind could form a link between the material being around your legs. It's kind of like how now your bladder knows it's okay to relieve itself when your on the toliet but not when your anywhere else. So wear your everyday underwear around the house and when you have to go just go. Yeah cleanup is gunna suck but over time it's gunna be enforced in your mind that you have no control.