You should meet with your therapist as often as is helpfull to you, if you are really motivated to work through something you can go multiple times a week , there are people who are still adjusting to what exactly they do with a therapist and only go once a Month , or people who started with one goal only to find a flood of emotions and feelings hidden away who feel very vulnerable and then there are people who are pretty stable and deep thinkers, so there time with there therapist is just the "launcher " for working things out in your head , when you have put something to bed , fire an email to your therapist and tell them where you are with it every so often and don't actually see them but a couple times a year , you have to decide what will be most helpful and supportive for you, of course I would suggest that early on in the relationship frequent contact 1. To establish ground rules 2. To form a therapeutic relationship 3. For transference and forming the bond that is essential in a relationship once you have done those essential building blocks and are ready to dig in you should also have some kind of idea how you wanna work and just because you say make a routine appointment every 2 weeks , nothing says you can't feel stressed and pick up the phone and make another appointment for sooner , the relationship should be flexible and as active or resposeive as you need it , there is also something people commonly misunderstand , just because you have an appointment doesn't mean that every time you go it had to be deep painfull work, I sometimes would go to mine and get there and decide I really don't wanna do any work, so we instead of having a normal session we would go out and go shooting or we would talk about genealogy , or the unusual pictures of family members of my therapist ( he had a picture of his great great grandfather dead on a rock ,in the same frame he had a picture of himself on the same rock in modern times , the great great grand father photo was taken by famous war chronicler Robert Burnside, where's the picture of him was taken by his son , this probably sounds really weird to you but to give you some context I live not far from Gettysburg battle field and his relative dead on the rock was killed during the battle of Gettysburg in service to the union army , there are literally thousands of photos of the carnage and the dead after a battle, to actually know the identity of one of the dead was somewhat rare , let alone to be directly related by blood to them and for the picture to be owned by the man's descendants is just friggin amazing 150 some odd years later) I hope I have helped in some small way to demystify the relationship, from what you have said you are dual diagnosis with a substance abuse issue did the doctor mention a medication like anti abuse or anything to help you from straying and indulging or had that jot been discussed yet ? Medication assisted abstinence can be very beneficial.

PEACE