Tips for longer hair

I cut my hair to my shoulders two months ago just for a change but now I'm over it. I miss having my hair to the center of my spine. I always kept it long. Seems these past two months not much growth has been happening like what I'm used to seeing or I'm over watching it lol
Any tips? Vitamins? Particular foods?
Miss my long hair. Kinda regret cutting it that short.