Thanks for your query.Based on the facts that you have posted it appears that you have benign enlargement of Prostate and have been taking alpha blockers and Dutasteride
to improve your urine flow and reduce frequency of micturition due to enlarge Prostate..
These drugs are known to have side effects of reducing libido due to their action of reducing testosterone
levels in blood.
You shall get your erectile dysfunction
to be normal once you stop taking these drugs.
Consult qualified Urologist
for evaluation and to change the drugs.