I was spraying my tilandsia 5 minutes ago and once I touched it a leaf just came off. So I picked it up and many other were loose, like the base was rotting. I thought I was underwatering since I barely remember it most of the times. It's not in the brightest spot, I might move it to my balcony. But could it be from overwatering? Or underwatering? Or lack of light?

if anyone could help me I'd appreciate it.