How on earth do I tell my fragile little Mom that she has to go to Assisted Living?

We took mom on tours, so she could see what was out there, meet some people and attend some events. She agreed to a one month trial. She ended up really liking the place.

My friend went into AL. The AL had a meeting with the family, one point they made was that by letting the facility take care of the resident, the son or daughter could show up and be the companion, be the son, be the daughter, not have to be the caregiver, housekeeper, etc..
My point is by having less have to dos for mom, you may have time and energy for more want to dos. Maybe you can sell her on that.

Only you can decide whether you need psychotherapy. What you need is to adjust your attitude about what assisted living is. It's not a punishment. It's a wonderful way for your mom to get the care and socialization she needs at this point in her life. She'll be around other people and be able to make new friends and participate in activities if she chooses. You and your sister can still see her as much as you want, but you'll be back to being her daughters and not her only companions and care providers. You and your sister have done what you could, but your mom needs more care than you can provide.

I'd get her into a facility and then look into selling the house. One step at a time. Once you know she's safe and taken care of, then you can focus on the house piece. This is going to benefit your mom, not hurt her. She may not realize that at first, but once she has people looking out for her, she'll settle in. If she's bordering on dementia, now is the time to do it, to get her settled before her condition worsens. My mom lives in independent living and loves where she is. She's 94 and has lived there since she was 81.