Testicular problems. pain a month ago. had ultrasound. now weak erection, occassional soreness and no pleasure from masturbation. causes?

See answer: The most common reason for a change in erection quality in a teenager or young adult associated with some degree of variable discomfort in the testicle(s), penis, and/or lower pelvic area would be a non-infectious inflammation or irritation of the prostate. This could secondarily cause psychological concerns, anxiety, fears, etc contributing to the problem. Not serious but can be complex to treat.