How to cope with my mother's depression?

My mother will transition to a long term care facility (nursing home) next weekend. I have been preparing her for this transition for the past few weeks. In a nutshell, she is outliving her money. She has been residing in an ALF for the past year at $6,200 per month, plus Medigap insurance premiums; life insurance premiums; medication costs; hygiene supplies, and incidentals. We have limited resources available now, and the ALF recommended we find a LTC facility before she actually runs out of money, so we will have more options and have her settled in before we have to apply for Medical Assistance. So she moves into the new facility on May 16. She has multiple disabilities from a brain aneurysm that ruptured 24 years ago, and she is wheelchair bound and overweight. She lived with me for a few years until it became more difficult for me to caregiver, and she transitioned to an ALF. However, she fell and broke her hip, which essentially caused more disabilities and lack of mobility. She needs 24/7 assistance now. Anyway, to make a long story short, I am feeling very sad and guilty that I have to make this difficult but necessary decision to move her to a long term care facility. We have no other option due to the fact that she is running out of savings, and now, her limited income (social security and my father's pension) will go toward paying for her nursing home, and Medical Assistance will pay the remaining fees and all other expenses. My father is deceased, and my mother and he divorced in 2010. How does one cope with the sadness and guilt for placing a parent in a nursing home? My mother is not happy with this decision. She protests that she does not want to have a roommate (there is no other option); and that she will not have her own bathroom in her room. She has dementia but is cognizant enough to understand what is happening. Her mood is generally labile (she has what is called "pseudo-bulbar affect from the stroke), so she can be negative and depressed; crying one day, and happy go lucky the next. It is very difficult to see her unhappy. Today I visited her for Mother's Day, and she was not happy. She is grieving the loss of my brother who died from pancreatic cancer in January; and another brother died a few years ago after complications from a spinal cord injury. She is grieving these losses, in addition to the lack of control over her life at this stage. She told my sister in law and me today that she does not have anything to live for, and she does not care about anything anymore. She is being treated for depression and anxiety with medications, and a psychiatrist visits her monthly. I am her POA, but I am at my wit's end trying to make decisions that will help her cope with these losses and her own aging process. Any suggestions from others who are in a similar situation? Thanks!