The divorce law in Washington (and really any state) is very complex and takes up several books. Far beyond what can be summarized here.
He does not need your permission to get divorced. He simply needs to file a petition in court. Washington is a no fault state so he does not need to prove anything about why he wants out of the marriage.
That all being said, you NEED a lawyer. Even a divorce lawyer that is served with divorce papers would hire another lawyer to represent them in court.
Your facts may not be attractive (winnable) or not winnable without a LOT of work and maybe not even then AND/OR you've set them out in a very challenging, obstreporous manner that suggests you'll be client from hell. Maybe you appear needy and/or controlling. Maybe you appear to be looking for some kind of personal vindication, which is an unlikely outcome of any type of litigation. Your expectations may be wayyyyyy out of proportion or you may be o/w setting the agenda in the way that will mean more work and personality trouble than pay-off. You may have aquired a reputation already in the small community of experts in that area of law in your jurisdiction and once that's established, it's hard to lose.
Try to remember that all an atty has to sell is time! It's not a volunteer outfit, either. Like everyone else, we like to be paid.
Best advice: Set out your facts - who, what, where, when, why and how much $$$, including a two-liner about what you hope litigation will achieve and whether you expect atty to work on contingency - in a one-page e-mail. If you need more than a page 8 1/2 by 11, take it back to editing. Try circulating that and see where you get. If no joy, test your facts here but with anonymous substitutions.