Hi Tuhinnazir,
Welcome to healthcare magic!
I think you are engrossed with the ideation of sex and are having performance
anxiety.
Masturbation is not a disease and it does not cause any effect on penis or body.
Size of penis which is more than 2inches is sufficient, with girth being unimportant.
It is the man behind the penis that is important and not the penis as such!
That the plain truth of sex, so build your confidence. Do work-out to build your physique and not the penis which is already good enough.
The masturbation is a strong stimulation and brings ejaculation early, in real sexual intercourse the same things do not remain the same.
You would be performing well I hope, just be confident and remain in good health.
I hope this advise would be helpful for you.
Still if you have any queries or doubts, please write me back,
I would be happy to solve them.
Wish you a great health!