Sue, I'm so sorry that you've been hurting.
Yes, I can relate.
Years ago, I often found myself drained, sensitive and anxious. Then...I think it was more of the flat affect that you described.
I have often felt isolated by this, but have come to realize that many more families than what appears on the surface have to deal/cope with a difficult child in their midst.
I still sometimes struggle with certain things, but not nearly as much as before.
One a positive note...Having a difficult child has made me more empathetic toward others. (Love your quote!)
I too have gone to counseling from time and time and have found it very helpful. The right therapist can be such a blessing.
AFter I made the decision to let go of certain things and to practice top notch self care, my life blossomed in a
VERY positive way.
Sending you good thoughts for strength and MUCH happiness! Hang in there!!!!!!!!!!!!!!