I have torn a part of this plant twice at my hometown, brought it to where I live now and then planted it. On both occasions, the plant started growing fine at first, but at some point, it started extending its stem and growing in order to reach the sun as much as possible (the top level entirely left the pot). What happened next in both occasions is that the old leaves at the stem started falling off and eventually the stem rotted, dividing the healthy top of the plant from the root.
I've tried replanting the leftover in the first case, but it eventually died off. Currently, I have the leftover of the 2nd plant which I tried replanting, but don't know what will happen yet.
I'm keeping it inside my office. It's facing east. During the morning it's very sunny, but in the afternoon it's not. I water it once per week, or once per 2 weeks.
Question: What do I do with this plant once it starts growing in length rather than in width and how can I prevent that? Is the problem that I have it inside the apartment instead of outside?
I'm trying to get it to grow and look like the picture on the left, but mine looks like the one on the right.