Is Carvedilol And Amlodipine A Good Combination For Blood Pressure Control?

I ve been on metaprolol for years and it was helping my heart rate stay steady and helped with my hypertension. New doc pulled me off this and put me on carvedilol 12.5 mg once daily. After three weeks BP is all over the place (higher and lower) and heart rate is higher than on metaprolol. Now starting me on Amlodipine 5mg. Told me that this is a strong drug and may lower bp too low. Is this a good combo? And how low is too low for bp (I check daily as directed)