ap481 - I am going to presume you are presenting a bona-fide case here with a sincere request for some advice.
May I offer a suggestion that has not been introduced yet? You have said that as a couple you have run the gamut of multiple therapeutic solutions. In your experience, has anyone proposed the EMDR method of counseling? It appears your situation would be ideally suited to use this approach, which is able to target and heal traumatic memories of either short or long duration, and of recent or long-past occurrence. Please do yourself and your spouse a favor and do some online research about this particular method of treatment. If you are able to locate a counselor nearby who is proficient in this, there are excellent, rapid results that can be achieved, in comparison to other types of therapy. If the practitioner is a Christian into the bargain - so much the better - but this is not a necessity for EMDR to be of real benefit on multiple fronts.
God bless your efforts at finding a healing solution, regardless of which angle He brings that help from. Whatever decisions you make about this should be based on the fact that “God hath called us to PEACE”. Our lives as Christians should aim for this peace within ourself, among others of the world if possible, and with our spouse. You have my prayers as you labor to achieve this.