I Have Been Diagnosed With Atrial Fibrillation And Borderline Aneamia.

I have been diagnosed with atrial fibrillation and borderline aneamia. I am taking beta blockers and iron tablets yet feel no better. I have had a heart scan and top left is slightly enlarged, my pulse is still around 100. What can be the underlying cause of this? It s 7 weeks since I was diagnosed and I am fed up with feeling so bad, what can I expect my doctor to do next? I am going to New Zealand on holiday and to visit my daughter for 6 weeks in 3 months time and am desperate to be well by then. Any ideas would be greatly appreciated.