In this case take what the doc gives.
Sounds like you have paranoid schizophrenia (correct me if im wrong) and you should stay on your meds. It sometimes takes awhile to find an antipsychotic that fits you well. If you dont like your Risperdal tell your doc and see if they'll try another with you, but I dont think anyone should be telling you what meds to take for paranoia for a few reasons, one being that most peoples paranoia does not come from the same source as yours, another being that since paranoia can stem from different sources (drugs, personality OR schizophrenia, they are not the same source) there are many different treatments for it depending on the source as well as different effects the drugs can exacerbate.
Basically, stay on your Risperdal until your doc can switch your meds.
Now, there are some SUPPLEMENTS (and probably some other things) that you can take, in
ADDITION TO your prescribed medication. Some have been tested in small studies on schizophrenic patients and others simply have anecdotal evidence. Maybe check some of those out.
Heres an example of a small list that is by NO MEANS EXHAUSTIVE! I have read in some other places other supplements/vitamins that
might be effective. None of this is really proven in large studies, but some have a few smaller (double blind) studies, others simply anecdotal evidence. Either way most supplements are harmless if they dont help. Check out these AND SOME MORE ON YOUR OWN!
Here