Lenny, I am very glad for you that you seem to have a found a direction to go in to try to resolve the matter. I definitely think that both going to a Beis Din and trying to get marriage therapy are excellent ideas, and I am very glad for you that you are doing both.
However, there is something that is very much bothering me about this situation as I understand it (and it is entirely possible that I misunderstood something). The way I understand things is that your wife has been miserable for the past 20 years. She hates you and considers you to be controlling and abusive. Whether or not you feel you are controlling and abusive, she clearly does, she is miserable, and she hates you. So why do you want to stay in this marriage? And why are you trying to force someone to stay in a marriage if she is miserable? And if that is what you are trying to do, doesn’t that seem controlling to you?
I am definitely in favor of marriage therapy. I definitely think that a couple should not get divorced until they have tried marriage therapy (in most cases, at least), and I am glad to hear you are going that route. Hopefully, you will find a good therapist who is able to hear and understand both sides and can figure out if your marriage is salvageable or not and advise you accordingly.
What makes me nervous is the fact that over the course of the past few years I have known several cases in which the couple separated but the get dragged on for years (in two of these cases, it hasn’t happened yet!) Off-hand, I can think of three cases like that (and there may have been more that I forgot about). I don’t know the details in any of these cases, but I do know that in at least two of these cases, the wife wanted the divorce and the husband didn’t. I am fairly certain that is the case in the third situation as well.
When I heard about these situations, I was shocked! Again, I don’t know the details, but something seems very wrong to me about a couple being separated for several years without a Get, especially if one side definitely wants the Get and the other is holding out.
I don’t know the details in these situations, and I guess it’s really not my place to judge. But I do think that this is a situation one should really try to avoid being in, and I hope that you don’t end up in such a situation. Hopefully, the Rabbanim and therapists you deal with will be able to guide you appropriately, and you will reach a resolution one way or the other, and hopefully it won’t take several years.
Hatzlacha and Gmar Chasima Tova!