Legal Advice- Live-in relationship

Hi, I(muslim) am 30 year old girl in a live-in relationship with a 32 years old boy (hindu) for 3 years and in a total relationship span of 5+ years. We have known each other since 17 years wherein he was my classmate since school. It started when he proposed to me for a relationship in college, I knew we cant marry thus I kept ignoring it for years. Eventually I agreed for a relationship cause I loved him since from the beginning I am sure he loved me too(it's a fact). We agreed that we'll marry each other with a firm decision about what may come. He used to live in Bangalore for work and I in Noida for work,  making 1.5 years of long distance relationship. Then I moved to Bangalore for work and he proposed a live-in relationship which I agreed to with my own will, making 3 years of live-in relationship. With this pandemic we both moved to our hometown(which is Agra) for both of us. Now with him moving back to his parents place, maybe he has changed his mind or he is influenced by his family's pressure or society. He is breaking up with me saying "We don't have understanding" after all these years of knowing and loving each other. I knew from the beginning that it's not gonna be easy keeping our religions in mind but I never thought even in my dreams that this man who proposed me in the first place, made all the heavenly promises is just leaving me with hollow words and blaming me with little quarrels that any couple will have in their lives. For him, it's all boiling down to "understanding". I am devastated, never trusted, loved or imagined myself with anyone else. He is a nice guy and I don't mean any harm to him in any respect whatsoever. I just want him to own his shit and apologies to me for leaving me for the pressure he couldn't bear. I too have also spoken at my home about him, they too are not in favour but I never left him, never married anyone else, thinking if we both can make them understand, eventually parents from both sides will agree. I want real reasons for him leaving me not these made up ones. Is there any way I can send him a legal apology letter wherein he would agree to what he has done to me and ruined my emotional and mental life, wasted all these golden years which will never come back and something I can move on with. I just need proper closure.