why are my mothers dying?

So i have these 2 mother plants, that were given to me about 2 months ago wen i first got them they were so strong full and growing like crazy. Have been keeping them alive but they are gradually turning yellow and wilting, this all has happened in the last 2 weeks whats going on? There 2 years old and were really strong plants, just trimmed them heavy time to see if i could start fresh figured all the nutrience could all be given to the small new tips but couple days later those branches started shriveling and are dying now.
Wat should i do i dont want them to die any suggestions?