celebgran - I could never begin to imagine the pain that would result from being cut off from children and grandchildren. I sincerely hope you do manage to rekindle the relationship you yearn for.
As for the councelling please remember that it does sometimes feel as though the sessions are making matters worse, it is part of the process, I felt exactly the same and sometimes still do.
Please don't let the pressures destroy your marriage but I do understand that the slightest innocent comment can seem like an insurmountable affront to your intelligence, It's what happens or so I am told, it's symptomatic.
As for coping tips, I'm afraid I am the last person to be in a position to answer as I am finding it almost impossible to cope myself. All I can offer is try to adopt a belligerant fighting spirit and refuse to be beaten. Easier said than done, I know, but it might help given time. At the same time perhaps be prepared to compromise, unilaterally if necessary, swallow all pride and say sorry in fact anything that is required to sow the seeds for a resurected relationship. It's not easy, not by a long shot but the life we have is finite therefore far too short not to try. It may not work but at least your heart will know there is nothing else you could have done or tried. Being honest with ourselves is a must.
I do wish you the very best and thoughts are with you - don't give up.