I would suggest that you have an ultrasound
scan of the soft tissues of penis without and with a pharmacologically induced erection. This would be able to tell you if there is a plaque
along the corpora cavernosa in which case you probably have an entity known as Peyronie' disease which is associated with induration of the penis with mild to moderate discomfort in it's initial stages. This test will also be able to quantify the blood flow to the phallus
and indicate if there is a likelihood of erectile dysfunction
which often coexists with Peyronies disease. The treatment would eventually depend on what is detected on the scan.
Hope I have been able to help you.