help me :(

ok so my bf and I have been dating for about eleven months now. his ex before me was a four year relationship. I asked him last night to tell me more about that relationship since it’s pretty intimidating.

he told me that she was someone his friend was dating and the friend was super hung up over her and they went to the same college so he (my bf) fell for her. they dated for two years and then she cheated on him. she begged for him back and he took her back and they went on to date for two more years. she helped him get good grades, but didn’t support his anxiety. when they broke up, he wrote her a long email and he said he really did care about her.

ok i’m fine with all that, his past is his past. but I just wanna discuss something. I feel like if my bf and I broke up, he wouldn’t write me an email or beg for me back. I feel like i’m not as special as she was to him. and it makes me so upset and triggers me because I would never cheat on him and i’d always understand his anxiety. he told me he loves that about me but I really want a guy that’s gonna fight for me if I leave. it’s not fair that this girl had two guys hung up on her and yet she cheated and they still are!! like dang what am I doing wrong? is it true that treating someone badly makes them like u more?? I would never do that but i’m starting to think it’s kinda true..