Blimey!  that's a pretty hard-nosed therapist!

and anyway, I really disagree with the assessment - your ex is gas lighting you, bad-mouthing you to others - of course you are going to care about that.  It's a form of attack.  

my ex still lies about me, wanting to cause me hurt, it's not going to stop.  It's had some very hurtful consequences, though his last effort (telling someone I was a lesbian) rather backfired on him.