An important principle to remember is that you can never change anyone else no matter how much you want to. What you do have control over is YOU, YOUR behaviour and how YOU respond to situations. The great news is if you do change yourself it may then encourage change in the other person.
Setting boundaries and changing your relationship with a drug user is difficult. It is especially hard if you are isolated and unsupported. Getting other family/whānau members positively involved is extremely important. Otherwise using the FDS support line 0800 337 877, joining a support group or even discussing things with a counsellor can be very helpful and empowering.