I'd say you've got a couple problems.
1) Charisma as a dump stat. Yeah, it stinks for that to be a dump stat, but it unfortunately is for a lot of folks. There are ways to make it important, such as campaigns that deal more with interaction, but other than that, there are few ways to make it vital. Everything else has a very definite purpose, rules-wise (attacks/damage, AC, saves, hit points, skill points), but Charisma is a flavor thing and a bonus or penalty on a few skill checks that may or may not be used for most characters.
2) Constitution is vital. If charisma is the one stat most folks can afford to dump, constitution is the one that most folks can't dump, ever. If you play a low-con character, you're taking the risk that one or two goods hits will kill you. If you're playing a low-con, lightly armored elf who is going to end up in melee combat, you may as well put some ranks in Craft (Woodworking) and start making your coffin.
If you want to go with the same character concept again, there's a few things to keep in mind. If you really are going with a tribe of sickly elves, they might have developed strategies like this - otherwise, their very existence is baffling, as low hp folks without good tactics are sort of doomed by natural selection.
1) I'm assuming you were doing it already, but you're pretty much locked in to being an archer. Be the best archer you can be. Archer feats, good bow, variety of arrows, the works. TWF ranger isn't going to last long for you - your six hit points are going to drop the first time you face an orc with a battleaxe. If you shoot that orc in the face while he's fifty feet away, this is much less of a problem.
2) As an archer, you're going to be standing back with the wizard of the party. Make friends with that wizard (put that charisma score you didn't dump to work... and threaten him

), and get him to hit you with spells that make you tougher or harder to hit (or both). Anything he can give you is awesome - Protection from Arrows can protect you from enemy archers, Levitate can put you out of a melee person's reach, and Grease can keep melee folks from charging you. In return, he gets a capable (if fragile) bodyguard in case enemies break through the front line and charge you two.
3) If you can't outlast an opponent, have a backup strategy to get away. Be faster than him (you're already faster than folks in plate armor, but the faster the better). Be more mobile (this is not faster. This is being able to go in directions he can't. Up trees, for example. It's cowardly, but if you shoot arrows from the tree at him until he dies or goes away, you still win).
4) Or be smarter - don't shoot the guy who is charging you, shoot the rope that's holding the chandelier above his head. If you're not dumping charisma, you might as well add a bit of swashbuckler flair. Don't play by your opponent's rules - those are all based around the guy with the most armor and the most hit points hitting the other guy until he's dead. You've got a 6 Con and light armor... you're very much the 'other guy' in that scenario.