I did not read through all of it, but are you DBing based on what you read here, or have you actually read either Divorce Remedy (a revision of the original) or Divorce Busting (the original)?
IF this is MLC (and it sounds like it could be) 20 months might feel long, but it could take twice that.
IF you are prepared to wait it out, then you need to get back onto the GAL train.
And stop talking about the D with your H. Lawyer up if you need to, but let the L's discuss the D and let your H take the pace for it.
