Demi Lovato got used to “not seeing hope” amid her addiction struggles. The 31-year-old star has been in rehab five times to treat her substance abuse issues, eating disorder and other mental health problems, and she’s told how she felt “defeated” each time she began in-patient treatment but eventually started to “find joy” as she worked on herself. Speaking during a discussion with Dr. Charlie Shaffer at the Center For Youth Mental Health at New York-Presbyterian’s annual benefit on Monday (03.06.24), People magazine reports she said: “I have been to inpatient treatment five times, and it has…