Toprol-XL and maxalt

I was given Metoprolol, a generic for Toprol-XL several months ago, for high blood pressure. It was prescribed after I was determined to be allergic to Lisinopril. ( It caused a cough that lasted 3 months; I sounded like a TB patient.) Anyway, I have been taking Effexor for years, for anxiety attacks. Now that I take Metoprolol along with the Effexor, I am so tired and drained all the time, that I am contemplating quiting work. I go to the grocery, come home and lie down. I can't seem to have energy to breath correctly. My Dr. won't believe that this has anything to do with meds. I have now developed blood and mucous in my stools, diarrhea, and very urgent BMs. This all started after taking these two meds in combination for about 4 months.