You could do both; it depends on what you are intending.
I do think you should contact OWH; You may be fearing to do it, because it could further drive your husband away. I don't know what the consensus is here, but my feeling is that our WAS's are already gone. What is he gonna do? Walk away again?
Both Puppy and Sandi recommended I file for D first, before my W, as a way of taking control of the situation. Understand, I did not want a divorce, and this is not what they where suggesting. It would've been part of me detaching and moving on with my life. Maybe it would've woken my W up. Unfortunately, I didn't take their advice, and my W filed first. She has been in the drivers seat.
I think you could file for divorce if you are trying to save your marriage, and you have reached a last resort situation. However, I generally think it's better to delay D as long as you can. Like they say all the time: this is a marathon, not a sprint.
hang in there.
M:42|W:40|D:17|S:13|Bomb:10/23/09 Awoken's Current Thread