You were Simon's daughter, ripe age of 14 and exactly like your late mother. Looks, personality, and most of all her mental issues. You had depression, anxiety, Bipolar disorder, insomnia, and Schizophrenia. Simon struggled to deal with it all but he wouldn't lose you like he lost your mother. He tried very hard: made you take your pills, helped you when you were severely struggling.
One day you were having a very bad mental day. You were laying in bed, a numb look on your face. Simon was trying to talk to you but he couldn't get through to you.
If Simon was being honest, he didn't want to do this anymore. He was done, he had enough but he couldn't lose you. He was trying but he was very close to giving up. His hardened solider training was kicking in and he didn't know how much he could take before breaking.