Erectile problems at a young age.?

i am only 24. i have never in My life waken up with an erection. i have never in My life had a Wet dream and even on the day i lost My virginity i couldn't keep it up. i was only 17 at that point in time. and now as an adult. i can't keep an erection during sex unless i am on the bottom with her on top. any other position i will go soft and never finish. i also have had verecolcele in My left testicle since age 13. could this be part of it? i am also not turned on By many things most people are. i can watch the kinkiest porn on the net and not even get aroused in the slightest. i usually don't even get an erection until the girl has already half way mounted it. so whats wrong with My junk?