Caring for my Mom has taken a toll on my daughter, now she's failing classes. How do you handle raising children well and be a nurse?

My daughter is 21 and a senior in college but she is failing her classes now where she began as an academic scholar. There are no drugs or alcohol involved nor boyfriends. She was always a good child but I have had to spend so much time caring for my Dad and now my Mom that she has just kind of had to raise herself the last few years. She says she is depressed and has contemplated suicide in the past which scared the --- out of me!

I sent her to the school therapist who spoke to her about home life and my daughter told her about the yelling and upheaval caused by Mom's dementia and the therapist's advice was simply, move out! My daughter and I both have no place else to go nor do we have the finances so this is out of the question. My daughter never returned as she felt this therapist was worthless!

I do not know how to handle this and my Mom, there are many times I am at my wits end.

How are any of you able to balance your home/family life and care giving especially when you are living with the parent who is ill.
My daughter means the absolute world to me and I cannot let something happen to her. There is no other sibling able to provide the care to my mother nor are there enough finances to put her into a facility.

I feel like I am stuck between a rock and a hard place! I need advice.