How do you make you hair grow really fast?

Okay so i use nexus promend shampoo and conditioner and i also use the nexus cream after i get out of the shower(they all help with split ends) it really works! I have straightened my hair twice this whole summer and i have no split ends really the ends are just really white my hair is dry so i use a once a week treatment on my hair the make it more healthy. I am gonna get my hair trimmed so it will grow but my hair just keeps looking shorter and shorter and suggestions i want it to be super long by the end of the summer! thanks! Also i highlight my hair every 2 months and i need it done again.