Ig this backstory was supposed to tell the MC's POV in the hopes of redeeming his character but it failed miserably. It's not your typical misunderstanding/miscommunication trope, he deliberately chose to be mean and be self centered. Why would you force someone who's mentally unstable, clearly delusional and actively living in his make shift world to have intimate relationship with you? You can't tell me that you're just going with the flow of his make shift world because that's what he's been living. You're the sane one and older person at that, you should've done better especially that you're well aware that you are one of the main reasons why he became like that