First, a bit of restating the obvious:
Isn't it a rule that after first level, you roll for your hit points? Isn't there a reason they call them hit dice? A fighter's hit die is a d10. Note the d. It means you roll a die. Rolling a die generates a random number. Thus it is possible that the random numbers come up low for you. WELL BOO-HOO.
Hit points must be rolled after first level. It's part of the game. Some PCs have low hit points, some have high. Maybe your Mage always rolls a 4 but your friend's fighter always rolls a 1. It can happen. Thus the fighter loses his hit die advantage over the mage. Such is life. Hit points aren't everything. Deal with it.
DMs out there: You must let the hit dice fall where they may. To do otherwise is to sell both your players, and the game itself, short.