Madre. I just want to say Hi, and welcome. You have gotten such good counsel. What I do know is there are always solutions. You are on the way to finding them.
I think you have good kids and you should feel very good about yourself. Raising kids alone is not easy.
Remember. The full story has not been written. Not for you, your daughter or son.
And remember this, too. None of us was a perfect parent. All of us are works in progress.
I agree emphatically that is not in your best interests to move in with your son. Nor is it in your interests to help financially either one of your kids. I would try to back off from daughter, too. Believe me, she will come around.
Within the next year or so you will be able to claim your full social security, if you have not claimed early. With that and medicare the majority of people make do, and way more. It will be a base.
I think you are on your way to handling what you need to. Basic security. Beyond that, it does not take much to be happy and content really. You are doing it.
For now, let your kids be. They are really equipped to deal with their own problems, and they will. I know from my own situation, wanting and needing them to be happy or successful or any other thing...is wasted emotion and counterproductive. Really.
Better we focus upon our own happiness and contentment. I am glad you are here. I hope you keep posting. It really, really helps.
Take care.