Loosing motivation to take medication [because doctors now say I don’t have schizophrenia]

Is it possible that the reason you have not had another psychotic break is because the meds are working? Talk to your doctors about adjusting or going off your medications.

Psychology remains historically a very new 'science' and many people would dispute that it is even that. A great deal of the knowledge of psychology relies on the experience of the psychologist themselves and their ability to use their insight to gain and understanding of what may be going on. Hence the process of diagnosing an illness is complex and doctors can give conflicting diagnosies based on their different areas of experience and expertise. This is why there is no overall single framework for psychology as it is very much a question of trial and error. (I think) Diagnosises are made based on 'clusters' of symptoms rather than on establishing a known cause. In some cases, there is a degree of scepticism over whether medications actually work, and in some can make the symptoms (such as depression) worse and can lead to addiction.

At this point I would just trust your therapist and be open about your doubts as it will help the doctor-patient relationship so that you understand each other and know what you are doing. I sincerely hope that you are one of the lucky ones who was misdiagnosed and I'm sure it will be a relief for you if that is the case but stay cautious and take the medications until your doctor says otherwise. If they do reach the conclusion it was a mis-diagnosis, I imagine they will take small steps to be sure and to play it safe.