How to diagnose penile fibrosis

Hello everybody! I am a 29-year-old man and had been taking duta for the last nine years. I never had a problem with erections. About 1.5 years ago, I went into benzo withdrawal. For some unknown reasons (maybe mental trauma ), my pituitary glands failed. And I had very low testosterone. I did not get a proper erection in that 1.5 years. Now I am on TRT, and my hormones are back to normal. But I have lost a significant amount of erection length and girth. I was wondering if this has happened because of fibrosis, will it always be showed on penike doppler test? Is there any other test which can find out what exactly happened to my penis?

Color duplex ultrasound