Drelmanes: I only did this quest after doing a lot of other quests. I think this mission is hard for you at this moment. Gain XP, raise your level doing other things, then try again. I completed this quest, but one of my NPCs haven't survived the tough fight with the mage. There's a lot of interesting missions for you in the Hive, just look around, talk with everyone.
WARNING! DON'T. TAKE. THE. BOX from a guy with dead insects around him. His name is Mar, if my memory don't fail.
Please ignore that warning. The box is a part of a quest which can be solved and you will be rewarded. Keep in mind that in PS:T there is usually a non-violent way to accomplish almost all of the quests. In fact there are only 4 places in this game where violence is absolutely necessary. This is why intelligence and wisdom are THE most important stats, since they allow for the most dialogue options, which not will not only provide you with interesting plot lines, but also provides you with the most experience. I usually start by only putting points in INT and WIS, then becoming a mage when I can.
Also remember to use spells and abilities when you're in trouble and need an edge. You can't just rely on brawn alone in this game, or you'll die a thousand deaths. Study the dialogue options, talk to everyone with a name you meet, and always offer to help if you can (unless you know it's an evil path, in which case it's best to not do it). Talk to your party members once in a while. That is another source for experience points, as well as providing interesting background information on them.
Most of the fun in this game isn't the combat. Instead, it lies in the characters and the story. I didn't enjoy my first game of PS:T nearly as much as my second, after knowing how the game worked, so keep that in mind too.