AITA For Not Walking My Friend Home?

Backstory - I lived with "Dee" for about 2 years after college. We hung out all the time, we'd go running together, & we had/still have a lot of mutual friends. I moved to a different town for a year for a job opportunity & she moved in with her boyfriend of a few years. Not long after they'd been living together, he tragically lost his life in a freak accident. While I certainly wasn't a perfect friend to her during her grief, I did not give up on her when she tried to push everyone away & I would visit/talk to her as much as I could. Earlier this year, I got permission to work remotely & moved back to the city & started hanging out with Dee more frequently again.

Main story - About 2 months ago, Dee, 2 friends ("Cee" & "Gee") & I met up to run a 6-mile loop early on a Wednesday. We're all training for a marathon so we run together often. We met up near Dee's apartment. We start our running loop & we're all chatting. About 2 miles in to the running route, Dee slows down while Cee & Gee are running ahead a bit. I slow down to be near Dee & ask her how she is. She gives me a thumbs up & says she's fine. She tells me to carry on running, so I do. Soon, she is running next to me again. About 5 min later we reunite with Cee & Gee. Dee tells us that she thinks she's done for the day & will walk back. We all ask her if she is okay & if she's sure she wants to go alone - she says yes & goes. Later when Cee, Gee, & I finish the run, I text Dee in our group chat to see if she got home. She says she was not home yet. I ask her if she would like a ride - she says no.

Something seemed off so I texted Dee separately from the group to ask her if she was okay. No reply. About 30 min goes by & finally she texts that she is home. I ask her if she is okay. No reply. Two days later on Friday, I text her to ask if she wants to go to the gym. No reply. On Saturday, she skips our weekly long run. On Monday, I text again to see if she was upset & if she wanted to talk. No reply. The following weekend, she skips the long run again. I text her that Sunday saying that I hope she is okay & that I'm available if she wants to talk or needs anything. Finally 2 weeks after the Wednesday run, she texts me that she was anxious during the run & had a panic attack when we all left her. I apologized for not realizing & not staying with her because that truly sucks to go through alone - especially away from home. She didn't reply. I've checked on her since & she'll not reply. She'll only go to group runs or activities that we're both invited to if I can't make it.

Yesterday Gee brought it to my attention that Dee was still upset with specifically me for not going with Dee when she walked home alone from our run while having a panic attack. Dee wasn't mad at Cee bc she doesn't know them that well & she wasn't mad at Gee bc they're a guy. She was mad at me for not sensing that when she said no, she really meant yes. Am I the asshole for not going with her?