Well, don't get scared away. You don't have to be Tolstoy in this business. That's exactly how I write. I do all my writing just like I'm sitting across the table from a friend of mine, or writing a friendly letter. It's just hard to read, that's all.
Conversational writing is the best, and the computer makes it easy.
If you can type with any reasonable speed, you can type faster and longer than you could write, without getting tired. Make a list of everything you know. I know, that can be easier said than done. You may think you don't know enough about much of anything to write about, but that's not true. All of your hobbies, interests, work experiences, etc.