Why Am I So Weak And Ill All The Time,

why am i so weak and ill all the time, have had yesterday a colonscopy its clear , have diviticular am suffering nausea ,loss of appetite, weakness ,all tests so far cannot give me answers is it possible i am over medicated? dr have me on blood pressure tabs, thyroid for under active, lipitor, nexium , clopidogrel had open heart sugery, procalm,motilium, axit, this situation has been going on near 4 years and is getting worse ,in the fact i am constantly weal and dry reaching ... HELP