Most doctors today will be very frank with you, the older doctors may have personal knowledge - if you can talk to retired doctors. If you use any medications or drugs, including alcohol, ask your doctor if that may be causing the problem. Use the Internet for searching on different areas that may shed more light on your impotency. A vacuum device is available that will bring more blood into the area. Prescribed drugs that you inject by needle can cause an erection.
Plastic implants can help provide a boner for a partner's pleasure.
Surgery can help men with inadequate blood supply to the penis.