I think that there will definitely be adjustments after 39 years.
I think it will be hard, no doubt.
And I don't mean to belittle the therapist for pointing that out -- but I would like to see it more like (sorry, I just think in pictures)... what you're doing when you're leaving an untenable situation is really saving your life, and whatever scars you get from that process are scars you'll have to deal with later. Right now, the important thing is that if you determine that the situation you are in is one that is breaking you down -- then step one is leaving that situation. Step two will be dealing with what happens later.
There are days when the pain is so overwhelming I have a hard time getting out of bed.
But there has not been ONE single moment when I've regretted leaving. Not one.