I had a Pacemaker put in on May 18th why am I still tired as hell?

In Nov. I had an operation (Hydracele) was healed up by Dec 29th, Then I had a super cold virus for 3 months,,that was the last of March. I was weak all the time and my doc did a stress test and ekg discovered I was in A-fib,,,did a cardioconversion and put in the Pacemaker. Shouldn't that get my energy back? They checked the Pacer,,everything OK there.