I have had really weak erections for about a year now. I am overweight but not massively. I am 19 years old and 15 stone . But a lot is muscle mass. I was on antibiotics for a urine infection and my erections over night became mush more frequent and ten times stronger. I could also maintain them for a lot longer. I finished the course of antibiotics after a week. My erections have gone back to being really weak and some of the symptoms of the infection are back. I was never told what infection I had, or whether it was a sti either. Any ideas?