While watching porn i usually ejaculate within 1 min but while doing imagination it takes time for my penis to get erect and generally takes about 5 to 8 mins to masturbate. But when my penis is fully erect I usually come within 1 to 2 mins.
More information would be helpful. Apparently you are referring only to masturbation, not to intercourse as well? Are you intact or circumcised? Are you a young "beginner" or an older, experienced "hand"? In either case, I would guess that abstaining for an extended period would actually speed up ejaculation rather than delay it. If you are intact (not circumcised) and a new-to-sexual-activity youngster, rapid ejaculation is not surprising (circumcision normally requires somewhat longer stimulation). Completely retracting the foreskin during masturbation or even for short periods during your daily routine (i.e., direct contact with the exposed glans of hand or undershorts) should help to gradually tone down your (over?)sensitivity. There are also over-the-counter desensitizing preparations to artificially delay orgasm....though I personally would not want to recommend them. But perhaps most important, Auntiejessi gives you two very good suggestions for delaying with either type of activity (look them up on the internet for instructions). Good luck---just concentrate on the old Cunard Lines slogan: GETTING THERE IS HALF THE FUN! :-)