How is your big belly?
Hey... are you trying to offend your friend? ...LOL
Your whole essay looks like one paragraph. However, it needs these features;
1. Identify the type of letter (e.g. formal/ semi formal/ informal)
2. Open and Close the letter correctly( e.g. open; Formal letter - Dear Sir / Informal Letter -Dear Sanz)
3. Open an informal letter with a general, friendly paragraph
4. Identify the main purpose of the letter
In your case it is an informal letter