bows are weaker than melee weapons. so what you need to do is practise your run and gun skills. do not try to kill anyone with a head shot from a bow, even at higher levels this is unlikely, unless your target is a rat or something low level like that.. and only if you are shooting with stealth bonuses applied.
bows are viable tho, and the bonus is, you dont get your armor damaged by all this close range combat.
also, in this game, if you have cash enough, you can make your own magic weapons. for increased damage with bows, try collecting poisons and coating your arrows with them, it can make a big difference.
good hunting.