Have I damaged my orchid beyond repair? I recently purchased my first orchid, a Phalaenopsis.?

It had 10 beautiful blooms and two unopened ones. I placed it close to a south sliding gl door. One of the unopened blooms opened. It did very well for 7 to 10 days, but I noticed that a couple of leaves were getting dark spots, like it was burning. I read the leaf color if this plant should be light green rather than the very dark emerald green like mines. A week later a spot on one leaf started to lighten. Initially, I gave it very little water. The second watering, 3 or 4 days later, I gave it at least a 1/4 cup tap water.. Now, I know that I have overwatered the plant and probably had it placed wrong (too much indirect light). The leaves have wilted and all except one of the blooms wilted and I think a fungus (white spots on one leaf) was developing. I have cut the wilted leaves and the fungus leaf. My question is, can this plant be saved? I am afraid of damaging it further. Should I place it in darkness for a few days? what should I do?