hey guys, just wanted to ask this question to know what people think. i'm a young guy (younger than 21) and i noticed i have a problem staying hard when the sex goes for a long time (20+ minutes). i have no problem getting hard at the start, or even by myself watching porn or anything. getting "up" is never an issue. but when i stop myself from cumming early (slow down for a bit during sex), i find it hard to get going again. i don't go completely limp but it's definitely noticeably softer and somewhat embarrassing. it even got so bad once that i had to act like i came in the condom to end the sex when in reality i just couldn't get hard. what's the problem?