For the lilies with virus symptoms, I would remove some soil above the bulb and clip the stem off. The virus transmits by aphids on the foliage. The browning leaves are a symptom of botrytis fungal infection, common when a bed is overcrowded. Enjoy the oriental lilies for the remaining season, then dig everything up in the fall, removing and discarding the diseased bulbs. If you don't have aphids or other sucking insects now, you have nothing to lose. Replant, keeping lilies separate from tulips (which can carry the color breaking virus). Lilies need a lot more space betweem them. In my opinion, I would not add any new lilies until you see how these turn out next year.

I bet your little garden is putting on a nice show in spite of the sad situation.