I feel guilty about wanting to move great-grandmother to a nursing home, but I can't take it any longer!

This is a very long story, so I apologize. 2 1/2 years ago my son's friend came to our house and said to me, hey my auntie died if you want anything out of the house, help yourself. My immediate thought was you just don't go pillaging thru a dead person's house! So we took a ride to the house, on the way over to the house the kid said to me, by the way my grandpa is still living in the house. I walked into this home, it was a diasaster, the woman died 2 months before, her diapers were still in the bathroom and bedroom, there was feces everywhere. On the couch sat gramps, who I thought was in his 80's, turns out he was 59 and dying of cirrochsis of the liver due to alcoholism. Being a helper by nature over the next few months, I cleaned up the house, throwing away 500 big bags of garbage. Got gramps admitted to hospital, became his POA, because his family wanted nothig to do with him. Didn't qualify for SSD, he hadn't worked in 30 years. It finally came down to getting hospice and placing him in a nursing home, he lasted a week, then passed. I listed the house, had it sold in a week. I should mention the aunt took out a reverse mortgage (worse thing anyone could do) so the bank was about to foreclose on it. This was a very stressful time, I figured now that he passed, the house was sold ,my job was done. Well, I met his mother, my son's friends great grandmother, gramps mother. Oh boy! She was in no better shape, clearly dementia going on. She is only 76 yrs old. Turns out the family was stealing from her, she lost 40 pounds, she herself was an opiate addict along with her great grandson and his father. The day her SS checks arrived, she would pay her rent then give all her money to her great grandson or they would steal it from her. The apartment was disgusting, great grandson would not move out. So I contacted an attorney, became her POA for medical and financial. I finally told the great grandson, if he was not going to move out, I am moving great granny to a senior community, which I did. Come to find out great granny was selling her pain meds to neighbors, scamming neighbors out of money, food and other items.Found out she was quite the con artist. She would always play the victim. Her daughter and granddaughter want nothing to do with her, by the way she is only 76 yrs old! I took her to have a neuropsych eval, turns out she has dementia and cannot live by herself. I just moved her! Well Medicare does not pay for Assisted Living but yet she is still too cognitive to go to a nursing home. So after some discussion with my husband, we moved her in with us last February. I finally made the decision to have her placed in a community based residential facility. I fee guilty, why I don't know because she has completely taken over my life! I can't work full time because I can't leave her alone for long periods of time. I am currently going to school full time for social work, take night classes because I can't leave her alone. She calls me mean, is very non-compliant with things that she should be doing for herself. I had to hide all the meds in the home, hers and mine, because I started to notice a pill missing here and there. When I do go to work, I make her breakfast and tell her to make herself lunch, but she doesn't she would rather sit there and starve, or she will eat junk food, which I now started to hide. She's obsessed with going to the bathroom or not going! She has been dropping her cigarettes, I found numerous burn holes in her clothes that were not previously there. I tell her to not answer the door when I am not home because we have two very large dogs, who go crazy when the doorbell rings, I am afraid they will knock her down, yet she will answer the door. Her inhibitions have dropped, using totally inappropriate language, the list goes on. Yet I feel so guilty moving her! What is really bothering me is I am going to school to be a social worker, yet I cannot even tolerate her! Could it be that I am angry at her family for not being involved? I took on the responsibilty for her yet I feel like I am abandoning her. We made it very clear to her when we moved her in that if it became too much for us, we would move her into a facility.
She does pay us rent, which of course will sorely be missed, but it is not worth the major stress she is causing me.
What advice or comments does anyone have out there?