Help editing long private messages

While sending a direct message, have the option to increase text field size so when you’re going to type a long message you can edit it comfortably before sending it. 

With that small space it is a very slow, uncomfortable process scrolling line-by-line in such a small window, not being able to read and edit everything at a glance because you can only read three lines at a time. Sometimes so desperate to go quickly that you go too fast and miss mistakes. 

This feature helps editing long private messages in a more comfortable, user-friendly way and adds better user experience because editing is so painful. Omg lulz