That's a healthy plant, you just need to tie it up with some dental floss or another soft string to a prop, like a stick or a rod of hangar. Eventually it'll get a strong stem, strong enough to support itself that you can remove the tying. Make sure you don't tye it too tie, just adequate enough for the plant to remain upright, even slightly loose is good. It stretched like that cause the light was too far away, or not strong enough.