Hi. Thanks for your query. Noted your history of left testicle being swollen and rock hard. You can feel the artery going to them and its hard as well. It has also made your penis deformed and have a hard time getting a climax when you can get it erected. It feels like somebody kicked them hard as they could, it comes and goes but hurts more often than not. The most probable causes are: - Testicular torsion - Severe infection of the testis and epididymis - Hydrocele formation. - Cancer This can be well diagnosed by an ultrasonography and color doppler examination. If required surgical intervention may be needed. If infection is suspected you need to undergo investigations of the blood and urine and ultrasonography of the abdomen too in addition to the ones I have mentioned above. And t get a long treatment with antibiotic and anti-inflammatory medicines along with plenty of oral fluids, scrotal support.