Most Helpful Guy
Hair is made of protein, so increasing your protein makes sense. The Japanese use olive oil in their hair to strengthen and add shine. Up to you if you want to do that or not. But on average, hair grows at about an inch or two per month, so you won't have to wait too long.
Most Helpful Girl
Definitely take biotin supplements because it is a b vitamin. You can start with 5000 mcg and work from there. My advice is that you drink a lot of water and consider taking chelated zinc. Be warned that your hairs are going to grow faster and thicker EVERYWHERE in your body. The reason I am going telling you to take zinc is because your acne may worsen as you progress with the biotin. I would also consider watching your diet and eating more veggies and high quality proteins. Castor oil (mixed with coconut and olive oil) can hep you grow your hair long.