How to deal with borderline mother as siblings have left town?

All of your insight is right on. Reading this again makes me see just how co dependent I really am. I have a great life- need to remember that.

My mother has BPD with dementia. I spent most of my life trying to make her happy & trying to get her approval. Guess what, I never got it and I never will. Granted I didn't know that she had BPD, but I lost a lot because I jumped at her calls. Now, I take care of her. However, once I can no longer do it I will put her in a AL or NH.
I wish more time than I can count that I would have stayed in NC and never came back. The only go thing was I was able to be with my dad his last years. That I am very thankful for and I would have never met my loving BF if I didn't come back home.
Please don't waste your time on people who don't value you. Remember we can't buy more time & there are no do overs!

Good luck

Guess I'll be blunt here. Could you ask yourself why you and/or your husband should be helping them more?  Is your mother legally competent to run her life? If so let her get on with doing so, by herself. Your job is not to "fix" her - can't be done in any case. She is unhappy? Not your problem  She and Dad show no gratitude for what you do? How about just stopping doing it? 

Could I suggest detaching big time? And remember, some people are not, and never will be, decent loving parents. You neither want not need the approval of these people.  Tragic but true.

If you keep putting up with their dysfunctional behavior, you are enabling them, which isn't good for either you OR them. IF you continue to see them, you can just leave whenever they don't treat you right; on the phone you can say you have to go, and hang up. They have a victim here, you, and you're letting them get away with way too much.

Umm ... leave town?

Well, not literally, but your siblings have managed to remove themselves from the toxic atmosphere surrounding your mother. You need to do that, too, without necessarily the inconvenience of physically moving.

Your mother's mental illness is Not Your Fault. Your parents' financial problems are Not Your Fault. Your mother's inability to manage her emotions is Not Your Fault. Whatever you have to do to protect yourself and your husband from your parents' irrational expectations, don't spend a minute feeling guilty about it! This is Not Your Fault!

I am very sympathetic to people who have mental health problems. I'll bet you are too, or why would you go into therapy? BUT allowing someone else's mental illness to make your life miserable does not cure their problems and just adds more misery to the world (which has enough, have you noticed?)

Get whatever help you need to "leave town."

Your first priority is to your husband. You know, you need to set boundries. You r entitled to your life. Mom and Dad have each other.