You may develop a mental dependency on it to get hard. I would cut the pill in half if I were you. You shouldn't need it at all, but if you want it you don't need that much at your age.
for me it is the opposite. i have a way harder erection now. it is like my body realized it can pump more blood into the penis. so now it just does that when ever im stimulated.
im doing kamagra btw (don't think it changes anything)
It is not common to need viagra at this young age 23. But in cases with an extremely small part, it is not able to stand up to the high stress of increased BP and outside forces. There is really nothing you can do for that, unless you wish to try natural male enhancement.