What do the voices say? Who are the voices? Why do their opinions matter? The only voice that matters is your voice.
Mental health problems have nothing to with drugs or their abuse- while it is true that drug use and mental health problems often go hand in hand, it is all too often seen as a 'drug problem' (thus refusing to treat you until you're 'not an addict') rather than what it is- self medication, a desperate attempt by the individiual to overcome the challanges that their own mind creates for them.
You need to seek professional assistance, if you are experiencing 'positive' (hallucinations of any type, messiah-type-outlook, strong belief that meaning exists for you exclusively- 'the newspaper has codes that only I can decipher') symptoms of schitz-ophrenia/otypal/oid PD then it is essential that you get proper support. My experiences with the mental health system in my country have been a systematic failure, but I live in a bumpkin country and the mental health system has a very quick staff turnover making it hard to form theraputic relationships.
As you've mentioned several anti-psychotics (which don't seem to have worked for you) and you still feel hopeless I suspect that you've been unlucky and ended up with a doc who just wants to pump you full of drugs until you're a docile little zombie, not actually help you overcome the obstacles in your life. From what I can see mental health is not a 'glamour' part of the medical system, it's full of incompedent naive do-gooders (who are infuriating and useless) and the C-grade med students who are pissed off that they have to work with 'the crazies' and are sending out CVs as soon as they get a job (hence the very high staff turn over)- so don't give up, keep looking for the psych who can and
wants to help you lead a managable and forfilling life.
However, I'd reccomend getting in contact with mental health
patient support groups and organisations, for instance:
http://www.intervoiceonline.org/
http://www.hearing-voices.org/index.html
I'm not sure how long this has been going on or what stage you are in your treatment (from guessing I'd say you're still at stage 1? Have you seen a specialist yet? Have you got a proper diagnosis?) If this is new and still very scary I'd suggest reading:
http://www.intervoiceonline.org/support-recovery/a-practical-guide
The core quote, and why I support the hearing voices network (despite not hearing voices, I want to organise an equivilant organisation for people with BPD) is ['we' refers to the psychiatric professsion, 'they' are the patient]:
“What this research shows is that we must accept that the voices exist. We must also accept that we cannot change the voices. They are not curable, just as you cannot cure left-handedness – human variations are not open to cure – only to coping. Therefore to assist people to cope we should not give them therapy that does not work. We should let people decide for themselves what helps or not. It takes time for people to accept that hearing voices is something that belongs to them.”
I do not suffer from schitz-whatever, I've been diagnosed with borderline w/ schizoid tendencies (which is a contradictory diagnosis, but whatever), but from my personal experience I got the most theraputic support from other, often older people who were also borderline- had gone through the same minefield I'm currently in and come out the otherside in better nick than they when they started. A close friend of mine suffers from schizophrenia (he's how I know about the hearing voices network and the patient-led mental health reform movement- it is the patient, not the doctor, who should be empowered) and he said that the 'self-help' groups allowed him to learn and develop his own techniques to manage his illness. He is now on minimal medication (more for moodswings than the voices these days), has a job, a girlfriend, a nice haircut and has three voices in his head that he dominates (he use to have five distinct voices, essentially through arguing it out with the voices and disempowering them two of them shut up completely and the other three can be talked down by his inner voice)- he has gone from being literally a crazy-homeless-schitzophrenic to working fulltime in a government department, sitting at a desk doing a job that he's happy with and pays quite well.
I'm not sure if any of this will be helpful for you, but you should never give up on yourself. Mental illness is just a big internal powerstruggle, but you can win. You define your condition- never allow your condition define you. Everyone hears voices- their own mainly, but some people hear distinctive voices. People who hear distinctive voices can lead happy and productive lives. You are worthy of having a happy life, you deserve a happy life- all you need to do is dedicate yourself to fighting for the life you want.
You are worthy. You are worthy. Fuck the world, but never give up on yourself.