My hair used to be really thick, and curly. But ever since I got it trimmed, its thin and straight? How do I get my curly hair back?

I am age 57, mentally disabled just looking to answer and ask questions, I live on the East Coast of the United States of America I try to give positive advice and keep things for real and I expect the same treatment in return have a Blessed day hope God Blesses your day with the best of health, happiness, Many Blessings.