The thing that helps me when family members try to drag me into their drama is to remember: "Not my circus, not my monkeys." Your siblings are definitely taking advantage of you, and it must stop. Shame on those people for continuing to put you in an impossible situation! But you are the one who's going to have to stop it; it is NOT worth attempting suicide over. Stand up for yourself and refused to be abused any further. Those children are NOT your responsibility. Again, "not my circus, not my monkeys". Good luck to you.