What is this and what do I do with it?

Hi all,

Ive had this plant for a few years. 



Its one of the only plants I havnt managed to kill off!

I like the little white flowers, so I dont want to lose it.

Ive noticed moss growing on the soil, so must be poor drainage. So probably root bound. 

My questions:
- what is it!?
- Does it look like it needs repotting?
- If I repot it, do I need a bamboo thing to keep it upright? (you cant quite see it in the photo, but it has a bamboo hoop that the plant is attached to)

Thanks