The fact that you did not experience serious side effects before does not meant that you won't on a next cycle. This is the worst part of side effects - they are unpredictable, so you never know when they will take place. Therefore, it is best to prevent them, and reducing the dosages would be a good preventive measure.
As for the stack of deca and anadrol, you most probably had ED because both of them increase prolactin levels, which can lead to this kind of problems. Add the deca dick caused by dehydronandrolone, and you would get all that is needed to mess with your erections.
Luckily, prolactin levels are easy to control with cabergoline taken at 0.25 mgs EOD from the first day of the cycle. Then, for the next time you will run deca, the most efficient way of countering deca dick is by taking proviron.