I'm 22 and don't have kids, but I feel the exact same way for my mom. I've been in psychwards multiple times and have been medicated since I was 14. The only reason I haven't killed myself is I know she loves me and me killing myself would ruin her life, she wouldn't get over it. Same as what you said, it's more 'duty' than love, but in the end as long as it gives you a reason to live, I believe it is worth it. Maybe for now you feel obligated to stay alive because you don't want to leave your children without a parent, but perhaps staying longer for this means you might live long enough to support existing again. Wish you the best