You can buy a bow and arrows from the vendor in the undead area. From the bonfire, go right, down the ramp, across the ramp to the two Lance skele's, there are stairs hidden by the boxes there you can go down and a vendor is down there. It only takes about 15-20 hits from any kind of arrow, I brought along about 40 arrows just in case. Once you get that, you will be fine.
You won't hit another wall until Capra. In fact, past the Gargoyles, the following two bosses are ridiculously simple with magic, especially the Titanite, since you don't have to fight ANYTHING between the bonfire and him to waste your magic on.