Hi. Can someone tell me what's wrong with my bamboo plant? It's been sitting on my desk for the past 3 years and it's been fine (at least to my untrained eye). But in the last week, the leaves are starting to slump over and the lower portion of leaves are turning yellow.

I water the plant once a week. However, I am an absolute novice at this and only recently started to pay attention on how to taking care of plants, so I'm sure there may be many things I'm doing wrong. Below are some pictures. Also, in the last month or so a new sprout came out of the dirt next to the bamboo stem, which has been by itself for the last 3 years.

Thanks for the help!