What books are you allowed? A Druid/Scout would be a good wilderness themed PC that would fill in for your Cleric/Rogue well. Now personally, I love the Sorcerer, but it may not be the best fit in you case. Hmmm....Warlock/Rogue - Max out UMD and get a wand of cure light wounds for your healing issues, use SA at range through Eldritch blast - it could work.
If the Druid/Scout - You halfling grew up near a tribe of Wood Elves who indoctrinated you into the druidic sect. The valley, however, was frought with danger and goblinoids were regullarly raiding the area and the near by human settlment. Thus your training was split between the two disciplines. Eventually the valley was saved, but it peace ruined for you somehow. You travel now seeking a new home, a new place to belong.
If Warlock/Rogue - Your halfling grew up in a vast city with lots of corruption. The circumstances of your birth are unclear, as your earliest memories are of livign on the street, stealing food to survive with a mixed gang of other small sized children (gnomes, halfings, maybe even goblins). You have a strange dark birth mark on your palm that frequently itches, you here whispers in the shadows around you but are never sure what they say, and you are sure someone is hunting you for reasons that have not been made clear. To escape this pursuit you have joined a band of adventurers, hoping that distance and strange locals will give you a chance to figure out what it going on.