Wat can make my hair grow? im 18. 2 yrs ago i dyed & straighten it a lot but stopped.its thick but not long.i can kinda see my scalp on my front side?

Depends: There are many reasons that your hair may not be growing well. Products that you are currently or have used on your hair are certainly one possibility, but your nutritional status, underlying medical conditions and other factors may be at play. I would see your doctor.

Short cycle: You say your hair is thick but not long - that means you have plenty of hair follicles but your growth cycle is short. Hair grows, rests, then falls out and regrows. That's the growth cycle, and its length varies from person to person. There is nothing you can do about a short growth cycle; your hair will never grow down to your waist. Adjust. Learn to like short hairstyles.