I think you may have misinterpreted your diagnosis. Based on the treatment you have described, schizophrenia does not seem to be the most likely diagnosis, because the treatment you are receiving is not the standard treatment typically used for schizophrenia.
It is possible that you may have depression, comorbid anxiety, or another condition for which this treatment has been prescribed.
Some medications can affect concentration, particularly during the initial days of treatment. However, as the brain and body gradually adjust to the medication and the underlying condition improves, concentration problems often improve gradually as well.
Next Steps
Consult your prescriber.
Health Tips
Try to sleep 7-8 hours daily.