I Am Really Concerned About Myself. I Am On A

I am really concerned about myself. I am on a methadone maintenance program. I have a desk job, and its very difficult for me to stay awake during my work day. Iv also been told I have really low blood pressure. I don't smoke or drink or take drugs. I am scared that I may fall asleep at the wheel while im driving. Is this spmething I should be concerned about?