.5mg of dex is not enough when taking dbol for most people.
arimidex is really only suitable for people that dont "need" aromatase inhibitors (basically the people that would be ok without them) because their aromatase and sulfatase levels are low.
if you have oestrogen issues, which are quite common, you really need aromasin or letro- or similar
also you should try adjusting your sodium intake (lowering it) and increasing your potassium intake.