Hello and thanks for the query.
Erectile dysfunction or ED is very common in adult man and almost all men are affected at some or other times so you should not feel embarrassed going to the doctor as you should always try to find the cause for your ED and that is possible only after visiting to your doctor and getting investigated for it properly.
Apart from psychological reasons,there are several other reasons for ED.
Common ones are
Cardiovascular
Diabetes
Alcoholism
Smoking
Obesity
Lack of exercises
Atherosclerosis
Use of drugs like anti depressants,tranquilizers,anti histaminics etc

You must visit your doctor to rule out any disorder.

We doctors at online have certain limitations with us and hence can not prescribe you any medicines.You have to consult your doctor for the prescription.
I hope to have clarified the matter however you can revert to me for any other query.
Thanks and best of luck.

---