Hi welcome to Healthcaremagic
is an anti Hypertensive , it shouldn't be taken with out hypertension
..,. hence better get your BP check, if the BP is normal then you can stop it... its good that you have stopped seartaline.... it must be taken for long time... sertaline does not have side effect of Erectile Dysfunction
... you are needed to be counseled..., ED is happening because of your feeling that you cant, think in positive manner, also take opinion of other psychiatrist
Hope I have answered your question..