Know it's embarrassing but go talk to the doctor.
There are many reasons including stress that can effect you. As soon as there is performance anxiety that then complicates the issue.
Among other things they will probably always recommend a look at personal health, diet and exercise.
Seeing a trained therapist that also uses hypnotherapy may be a good treatment program.
Listening to a file - is not.
This is no long erotic or recreational when being used to treat a real problem.
In fact I would suggest that erotic hypnosis which attempts to control, limit or in any way focus your erection inducing habits is counter productive.