I started mastrubating as a kid at age 12. I would have pretty nice orgasms, then at 19 I started jacking off quickly to save time and dry mastrubating to save time, this made it worse because I have calluses from lifting.
It made me a fast shooter, unready for something that's not a hand, soft slot, and damaged my dick because of my calluses.
I managed to fix my dick though, now I'm good. Here's what I did.
>make body healthy
Exercise, get plenty of sleep, eat right, (I did high protein, high fat, low carb), and at least 8 glasses of water a day
>increase blood flow
Did stretching and self myofascial release (massage) a couple of times a week and took fish oil and l argantine
>Treat dick right
Never dry mastrubate, always used lube or lotion or a fleshlight, softly massaged my dick as I jacked it off
>trained my dick
Only came up to 3 times a week, did kegels (even did variations at work and while I was taking a leak), did pelvis exercises, edged myself, and made a rule where I was only allowed to cum after 15 min of jacking it. Also mastrubated in different positions.
I did all of this after writing it down as if I was making a work out plan. Your cock is a body part after all. Its not as overwhelming as it seems. I last long now and my cock gets rock solid once again.