Addicted... needed story ideas...relationship memories triggers trauma memories try using Emdr therapy.
A PTSD therapy used to sever brain lineages to severe memories of trauma. Detailed history is recalled to trigger memory. Following light during therapy as the link is severed. Also memories are stored chemically in the muscles not just your brain. So during flashbacks or traumatic memories places in your body will hurt also.
Also with as much as your character has gone thru, I would expect a mental condition of some sort. Possibly disositive amnesia, which is your brain not allowing you to remember something that would shatter your mind.
It happened to me.....10 yrs...childhood trauma
1970's...phsyco tried to kill me twice
Spouse poisoned for 33 years.. no cure
Difficult life, I survived, I'm happy.
Focus on something you are passionate about every day and you can get thru anything. I get thru with art, and beautiful things and find truth.