WIBTA for not talking to my friend about being distant?

I (F) have recently been going through a hard time. I don't really want to get in to it but because of this i've been pretty irritable and distant with some of my friends. I feel horrible about it but I just needed time away.

However, recently i've been getting back in to the swing of things and started being there more. My main friends consist of J (M), B (F), and M (F). Although I truly love them all, we mainly communicate through a group chat, meaning we don't text each other personally THAT often.

A few days ago, J brought it to my attention that B confided in him and is really upset/ sad about my absence thinking that i was gone to distance myself from her specifically. Now J and M both think I should text her that I'm not mad at her and just needed time for myself.

I am uncomfortable with this for a few reasons. 1) I didn't really ever text her personally to begin with, basically only in our group chat, which I've been regularly responding to AND have been talking to her specifically as well. 2) I don't like that B hasn't said a peep about it to me directly. She told J and from there it spread. But now I'm expected to talk to her out of nowhere ? and 3) As I mentioned earlier, I'm struggling with my own mental health and needed to distance myself from EVERYONE, why does B just think it's about herself and moreover, why didn't J tell them something instead of letting her think that?

Don't get me wrong, I think B's feelings are valid and I can understand being upset at the situation, but I just don't think this should be my responsibility to bring up/ apologize for. But if i don’t I fear all my all my friends would be mad at me/ think i’m selfish regardless of what i say.

So WIBTA for not communicating with her?