How can I overcome impaired attention while practicing to get a Driver’s Licence?

I stopped and went through a withdrawal process to get off the antipsychotic, Risperdal. (Always listen to your doctor to avoid harm). So I am practicing driving and am doing well, it is just, well, kind of stressful for me, because my attention is scattered. I don’t think I am ready to get my license, but I would still like to address this issue I am facing. Do you think Medical cannabis could slow down my brain? I do exercise regularly and eat healthily.