Author Cheryl Strayed has revealed that her husband, filmmaker Brian Lindstrom, has been diagnosed with a “serious, fatal illness.” The 57-year-old writer, whose memoir “Wild” was adapted into a 2014 film starring Reese Witherspoon as Strayed , apologized to fans as she was forced to cancel her upcoming appearances amid her husband of 25 years’ health battle. “My beloved husband Brian has been diagnosed with a serious, fatal illness,” she wrote on Instagram on Thursday. Cheryl Strayed announced her husband Brian Lindstrom has been diagnosed with a “serious, fatal illness.” Instagram/cherylstrayed “For that reason I had to cancel my writing workshop at Kripalu and also my appearance at Hunter College this week,” Strayed added.  “My apologies to those of you who made plans to be there. I simply cannot do anything but be with my family right now and see to our broken hearts.…