@Captain24 conquer or...gently work through? Language matters, and one of those options sounds a lot harder than the other! Just sayin 😉
Hmm maybe you can talk to her about the SP as well? You could introduce a specific section for coping tools and self-soothing strategies that are super low energy. Or ask if she can help you figure out some new ones to add in, or alternatives, you know just stuff like if the main section says do 10 minutes of mindfulness, this one might say do 2 minutes - makes it more approachable! If your SP itself has potentially become a source of shame, then no wonder you don't wanna use it!!
That is okay that you can't be there for her. Imagine for a moment your roles were reversed, would you be mad at her for prioritising her own needs? If the guilt is super intense, you could flick a message that just says like, you do really want to be there for her, but because you've got stuff you're dealing with too, you wouldn't be able to be there in the way she deserves, and maybe point her towards a crisis service or something so she knows she still can talk it through with someone if needed.
Or don't do that, conserve every ounce of energy you have, and message her later. Also valid.