When deciding to file for divorce, do good times out rank bad times?

I am contemplating divorce. I am going through all the things that I cant stand about the way he treats me. I also have thoughts about being alone. I entered in this marriage faithfully and with the perception that it is supposed to be forever. Do I have to wait till things are completely out of control? Mental abuse and his behavior is affecting my job. Long story short when do you know its the end?