Everything you wanted to know
When to file for divorce is a question only you can answer (except, unfortunately, if your spouse has filed or files first, then you will be thrust into a divorce, even if you aren’t or weren’t ready for it). A good lawyer or friend or therapist will not tell you that you must file. All they can do is to tell you what they advise or what they think may happen if and when you file. And no one ever knows for certain what will happen. So what should you do? Be prepared. Read, learn and consult. Read everything you can about the process and consult with whoever you can, but do your best to find those respected in their professions. I recently wrote a short piece on this which you can find at: http://nextdivorce.com/magazine/issues/premiere-issue/everything-you-always-wanted-to-know-about-divorce.
Divorce is never easy. Though some cases are shorter and simpler than others, they always involve emotions across the spectrum and it may be hard to think rationally when going through the process. So learn as much as you can, think about the consequences of acting hastily, and then, after you have consulted and read and learned, be sure to make the decisions you are comfortable with. It is your life and you will live with the results, so think things through, get as much advice as you can, and perhaps do your best to try, if at all possible, to act rationally, not emotionally, even though the emotions can be overwhelming.