Thank you, Amyjay. You're right. I texted my t and she said I'm honestly sick and I just need to tell my friend that. Of course I feel guilty because as soon as I cancelled I fell asleep for a couple hours and then felt fine. I told her I'd make it up to her. We will spend the day together tomorrow but I'm not going to offer her to stay the night. I should have discussed it inside before I made her that offer in the first place. It's a lesson learned. My t is always reminding me to check inside and make decisions with my the others instead of for them, as much as possible.
It wouldn't be good if she stayed over because I'm sure some of us would have been mean to her or otherwise alter my behavior around her. That was a good point you made. I sort of wish I could explain it to her but she's not someone who would be able to understand, and she has the habit of telling other people's business to those close to her, which wouldn't be good at all. She's been my friend for years and I have a feeling of responsibility toward her. She needs help in life, and can be draining, but she can't see that and doesn't have the ability to change that about herself. She also wants to be closer to me but I maintain a distance for all these reasons and more. More than anything I wish she could accept, somehow, that I just can't be the best friend she wants me to be.