ejaculation problems

Hi, I"m a 23 year old male and have been sexually inactive for about 2 years now. I masturbate about once a day and have had no problems doing so. I just recently had a most discomforting ejaculation. Upon ejaculating I felt almost a numbing feeling in my testicles. And the worst part, there was no sperm. I have been experiencing a discomfort in my groin area including around my right testicle. For the first 5 to 6 hours i constantly had to urinate but with no pain during urination. More than 12 hours later i still feel the discomfort. About 3 to 4 months ago I had an ultra sound for discomfort in my right testicle and it was found out to be just fluid build up. During that time I experienced pain in my groin area on my right side. My doctor said it was a muscle pull and and prescribed me a muscle relaxant. Also during that time I was experiencing irregular urination in which I was constantly urinating. To this day I feel discomfort in my groin area and my ejaculation just heightened that discomfort to both my groin and my right testicle. I have no clue whats going on here! just a little concerned. I have little or no faith in my doctor. What should I do. I'm concerned it will happen again when I ejaculate. It's been psychological terror just thinking about it!