Answer:
I will use more of a psychological, than healthy facts.
Explanation:
"Hey mom and dad,
I am grateful for everything you went through to keep me alive, both of you worked your arses off to keep the food on the table and give me education. Look at me now I am growing up, making friends, looking for a partner (or I have a partner) and like you guys I am planning to make a family. The only way I could be thankful to you is by leaving a cute and tiny grandchild as a memory in this world. I want both of you to be there not only for me, but for your grandchild too. I dont know how long it will take but if none of you promise me you'll try to stay healthy and safe. I will regret it for not going fast enough but, if you want to give me more time...then please... stay healthy. Do it for me, for my child, your grandchild for a happy future. I will support you in every way I can, hell! I will start training with you if needed be. Only promise me one thing, dont leave me yet, not until we make our promise come true.
I will always love both of you,
Your grandchild is waiting.