I Am Taking Coreg For Blood Pressure For A While

I am taking Coreg for blood pressure for a while now but the last couple month have had problems and pain in my biseps and have absolutely no energy. Now for the last 4 days have only been taking it at night and feel 100 percent better during the day and arm pain has lessened but am worried about my blood pressure. Does this make any sense? Am going to talk with my dr this week.