Tatum O’Neal’s son has penned an open letter to his actress mother, in which he writes that he often blames himself for her overdose in 2020.  Tatum had a severe, near-fatal stroke in May 2020 following a drug overdose that resulted in a six-week coma and lasting damage to her speech and memory.   In the pre-Mother’s Day letter shared via his website on Thursday, May 7, 39-year-old Kevin McEnroe wrote that he often believed that she would attempt to kill herself if he didn’t pick up the phone when she called, “until one day I didn’t answer and you did.” © Getty ImagesTatum O’Neal, pictured in 2018 “Boundaries, everyone says. I used to tell them that they didn’t understand. That if I didn’t answer your call, you might kill yourself. Until one day I didn’t answer and you did,” Kevin wrote. Tatum has since been diagnosed with aphasia, but through consistent therapy worked on regaining a full memory and grasp of her vocabulary. © WireImageTatum and her son Kevin in 2015 Kevin also shared that …