Your spouse is trying to keep control of your life and your marriage. It is predictable that she opposes your every effort. You're the closest person in her life — what is closer than a spouse? — and thus her disordered behaviors are much more evident with you than what other people view, others only get incidental glimpses of the deep problems and issues.
If I spoke to a woman I was having affair, I wasn't allowed to see my friends.
I recall pulling up to a stop light and my then-spouse got enraged because I was looking ahead and an old lady was crossing the street. She wouldn't believe me that I wasn't staring at the old woman. It got to the point I often looked down, I couldn't bring myself to look at other women for risk of her starting another rant.
She would max out my credit cards all the time and I was the bad guy for not getting a bigger limit.
Fortunately I had my own credit card account and years before I'd helped her get her own card account. Since we didn't have joint cards — often a real hassle to shut down a joint account — as soon as we separated I cut up my cardholder card on her account and I called my credit card company and canceled her card on my account.
She refuses to sign the separation documents because she doesn't like the wording, she wrote it. Or she wants "he will give me money as I see fit" written it.
I engaged a lawyer but she ghosts them, she says to me she will only open the email if I give her $5000.
Once the legal process starts, then her ultimatums or demands become weakened. The reality is that divorce court is here to be the passive referee. But it WILL get done, it will take longer than you expect but it WILL happen. She won't open the letter or whatever? Fine, your lawyer will have her served. If there is to be a divorce, one spouse can't stop the process. Period.
It may not be a totally fair divorce but it will most certainly be on better terms than she would dictate.
In addition to
Stop Walking on eggshells, be sure to get the best divorce handbook available: William Eddy's
Splitting: Protecting Yourself While Divorcing Someone with Borderline or Narcissistic Personality Disorder. Get it now. It's that important.
By the way, in the past when you were trying to improve the marriage, it was correct to share information, trust is important. But with the marriage ending, your priorities have changed, you need to protect yourself. Do not share anything that could sabotage your future. For example, if you share children, then obviously you would would share appropriate parenting information. But little else.
Don't share your goals and strategies. If you share what ought to be confidential between you and your lawyer then you could end up sabotaging yourself.