What are some ideas that i could use to write a gratitude letter to my parents with?

i know this is sad but i can't think of anything. i have to write this for graduation. respond sooner than later plz.What are some ideas that i could use to write a gratitude letter to my parents with?
Is this a school assignment? Even if it is not (and I hope you do feel some gratitude for them) you can include things that helped your development, especially the academic. I appreciate that you read to me every night because reading now is a real pleasure. It has helped me be a better student. You helped my physical development by getting me into Little League where I learned how to play on a team. You had me do chores around the house, so I learned to take responsibility for the space in which I leave and to help the people there live more comfortable lives. Playing board games with you helped me become a good winner and a better loser. You made sure that I was comforted when I was afraid which has made me more confident. You allowed me to make decisions so I learned how to learn to live with the consequences of them. You saw to my religious upbringing. You bought me that bicycle I was dreaming about and taught me how to ride it. You had confidence that I would learn which made me braver - I could fall off and get back on, determined to conquer the task. Stuff like that.