OK....back now.
Well, from 1000miles away it looks as though you might have an electrolyte problem, possibly a loss of potassium made worse by your diuretic Frusemide.
The quick way to support or disprove my diagnosis would be to ask your GP if you could have your blood electrolytes measured......simple blood test.
The slow way would be to eat 3 or 4 bananas a day and the odd orange thrown in and if your cramps improve, then my diagnosis is confirmed, but if not, i will give you your money back ;-)
Yes, yes, I know you also have Type2 diabetes, but my answer still stands.