Brassidium? Brown leaves and black spots

[MRey13]

Hi! I'm new to this forum. I joined specifically to get help with my orchid that I just purchased, and probably help with future orchids, hah!

So, I bought this plant about two weeks ago, because it had healthy looking roots, many pseudobulbs, and leaves. There were several spikes (about 8 total), some of which had unopened flowers. Anyway, within a few days of bringing it home, the flowers started dropping, including the unopened blooms. So, I cut down all the spikes that were dying with sterilized garden scissors, and removed some of the dead leaves.

I uploaded pictures of the plant before, and the plant now. Any advice would be helpful. I'm not sure what the name of it is, but it has a tag from Matsui Nursery that says "Odontoglossums/Oncidiums intergenetics." As you can see, there are various brown and yellow areas, black spots, and the pseudobulbs are beginning to look shriveled. The roots look okay to me.

I watered it once, yesterday, with about a 1/2 gallon of filtered water and a tiny (less than 1/4 teaspoon) of orchid fertilizer because it seemed so, so dry, and because of the shriveled pseudobulbs. I don't have any direct sun light in my apartment, but it was six feet away from a set of sliding glass doors that face south to a large covered balcony. I moved it further back in the room where it still receives indirect light, because I was afraid it was getting burned.

Any help or advice on what's going on with this plant would be appreciated! Also if anyone knows the plants name, I'd love to know. Thanks so much if you read this—sorry it's so long.