birdie, i can only give an opinion on the post that you have given and that does indeed lack some vital medical details I'm afraid.
To sum up, based on your medication, you have had high blood pressure for many years which is now controlled ( I assume) but it has had a negative effect on the pumping of blood from your heart. However,your medication would have stabilised your BP and also relieved the strain on you heart by slowing it down and reducing the force of it's contractions (beats)
You medication is standard treatment, well received, well tried and effective.
In this state of cardiac care irregularities are not that uncommon, but there are many types each differing in urgency, severity and treatment. They can be permanent (there all the time) intermittent (come and go) and if they are the former, it can be irregularly irregular or regularly irregular and only an ECG can determine which.
My guess with you is that the heart irregularities are intermittent (paroxysmal)
Dilzem....will ease the load off the heart and open up the blood vessels to give more blood to the heart muscle.You haven't mentioned chest pain, but they will also relieve that should it be due to angina (not enough blood going to the heart)
The anaemia is another problem that will need an explanation.
You certainly are "a creaking gate"........but as the saying goes "a creaking gate lasts a long time."
If I haven't answered your post adequately do not hesitate to get back to me.