Urgent help needed with Cattleya division that has gone downhill

[BrassavolaStars]

I have this Cattleya that is very important to me. I recently repotted it as it had a new root, and a new growth forming. When I went to water it, I accidentally knocked the new growth off, and it has been all downhill very fast from there. The leaves turned yellow and fell off, and it looks like a lot of the active eyes have turned dormant.

What do I do? I really can’t stand losing this one.

I was wondering if the fact I sprayed it with copper fungicide after the growth came off is responsible. It also seemed to dislike my greenhouse, which while average 55f does get below 45f for a few minutes every hour while the heat cycles.

Any help is appreciated. I don’t really have any good roots unfortunately.