The only way you'll find out if you "have it in you" is to get to work and see if you do. The only way to override your "limitations, insecurities, jealousies, and ineptitude" is to produce. You have limitations. You are in some way inept. This is true of every writer, and it's especially true of writers who are twenty-six. You will feel insecure and jealous. How much power you give those feelings is entirely up to you.