Hello!
I empathise with you. Seeing your loved one in pain and suffering that too for such a long time is difficult. But I am proud of you for all your patience and support towards him.
He needs to be shown to a psychiatrist, who will diagnose him for his current symptoms. His medications also might need to be changed. Doubting others intentions, talking to one self and living in an imaginary world all need medical attention.
You please take him to the psychiatrist , once he starts the psychiatric meds, things will come in control and other symptoms and complaints too can be worked on.
Next Steps
Take him to the psychiatrist immediately.