Do tell your therapist, she would be more bothered if you didn't. It's up to them to decide what they can and can't do and what their boundaries are. If you stay within that she won't feel bothered.
I hope you have stayed as safe as possible, sorry I wasn't up to a proper response earlier. I am thinking of you and rooting for you. I really really hope you can get through this and I think you can.
Well done going back to work and lasting the day, sounds like that was a huge achievement in itself!
By the way, you may feel like 'a piece of crap' but to me you're a valuable human being, worth as much as anyone else you can think of. Be kind to yourself, as best as you can.