Aio : Can't manage emotions after the break up

I had two relationships and a few friendships in my past before I met my recent ex. I met him through a game, and I was the one who proposed the relationship, which he accepted. Shortly after, I faced a serious medical emergency that left me bedridden for three months, during which I was strictly not allowed to use my phone. As a result, I could not stay in contact with him. During this vulnerable period, I sought help from a friend, but before I could even explain my past to him myself, my ex contacted this friend directly. Unfortunately, she exaggerated and spoke negatively about my past without my knowledge. When I resumed contact after three months, his behavior had completely changed. He became controlling and constantly doubtful. At that time, I did not understand what was happening and began to obey him out of confusion and emotional attachment. He repeatedly questioned my past, and believing honesty would help, I opened up to him, even though we had barely known each other before the sudden break caused by my illness. Later, I discovered that he and the same friend were regularly video-calling each other and speaking badly about me. When confronted, he justified this by saying he was trying to “know more” about my past. I also found that he was in contact with his former crush, which he excused by blaming my absence and emotional unavailability during my illness. As time passed, his control intensified, extending to every aspect of my life, and this severely affected my emotional stability and mental well-being. In 2025, I came to the painful realization that he never truly loved me and was only interested in me physically. Even after the breakup, he continued to emotionally manipulate me by trying to remain close and using his distress to keep me attached. I finally walked away when I understood that he was cheating with multiple people and repeatedly blaming my past for his actions. After the separation, he began defaming me to his family, friends, and others he interacted with, portraying me as a bad person. As a result of this prolonged emotional distress, control, and character defamation, I am currently struggling with negative thoughts about myself and my self-image....

Would anyone please tell me if it's my fault.... I just don't know why I keep blaming myself.... It's just too much