Hi Lisa, just read your post and wanted to tell you I understand how you feel. My son who is now 18 was diagnosed with psychosis two years ago. I felt as if I had been kicked down a well and couldn't see how to get out. My son had also smoked cannabis but we will never know if that was what triggered things or if it would have happened any way.
Fortunately he has responded well to medication and leads a normal life. I also have fears about what the future might hold but I am amazed at my son's outlook. He gets on with life and has the same dreams and aspirations that he always had. He doesn't mind telling people that he takes meds for psychosis and as yet has not come up against any discrimination.
I feel he is still quite a vulnerable lad but I try to take a leaf out of his book and get on with things as positively as I can.
I hope things are getting better for you and your son.