Is that tin or aluminum foil on the wall? If so you should remove it. They don't reflect much usable light at all and are likely to cause more harm than good.
Your plant is also nute burned and light starved, and it looks like you don't have a fan blowing on your plant either, which is one reason why your stem is so scrawny. You'll notice that you have one stem with fan leaves, but no lateral branching. That is a sign of weak lighting. What bulb(s) are you using?
What soil are you using? Are you using tap water or spring, mineral, distilled, or RO?