dary:"Anyway, I don't know how to deal with this. I try my damndest. I guess I feel guilty because their lives are not better. I honestly don't know."
SpaceAce:"Something that you left out of your post is the overall lack of cooperation you get from these people you are taking care of."
It sounds like the dominate focus in all this is what They Need From You. Maybe you should meditate a little on YOUR needs. Then communicate your feelings to them with a redirected Focus of What You Need From Them.
You might try some CODA (Codependents Annonymous) meetings. It's much easier to do what You need to do with the support of others working on similiar problems. Also some visits to a Profesional Therapist might help. You don't have to take on this task alone.
Here's a good link for symptoms of codependency.
http://www.coda.org/codapatt.html
PairTheBoard