I'll quote you in bold, and I'll try to give more feedback tomorrow. Not too up for this place today.
she is depressed the MC went into that last night she won't take meds. So she sees her T twice a week now.
Saw earlier depressed? MLC? Does it matter? She's going to do/say/feel whatever she's going to do right now, and there's nothing you can do to change that and/or speed it up. This is something she'll have to work out on her own, and at her own pace.
1st time I had a major depressive episode, I resisted taking ADs for a whole month; didn't want to do it as it was just another reinforcement to me of my own weakness.
I guess I want to know the unanswerable.... will she come back to me.
You don't know. She probably doesn't even know this yet herself. It's pointless to try to figure out what's going on in her head right now, as it's most likely a jumbled mess of confusion.
Best things you can do right now:
Become introspective and figure out how you contributed to your current sitch (and know you did, whether you want to realize it or not). This is not all just her "taking leave of her senses", so to speak, in her mind, she has some reasons why she feels this way about your M, most likely because you weren't filling some of her needs.
Get active. Start doing things to occupy your time/thoughts.
Read. Read. Read. Get educated, since forewarned is forearmed. (I'd recommend DR/DB, 5LL, also When bad things happen to good people). Other people's threads.