My so called friend is torturing me to marry him

Hi so i met this guy in an online chat app some 5 years ago. I was in my 11th grade(i was 16) and he was a good friend. He proposed to me and i refused as i had a boyfriend that time but still kept in touch with him. After i joined my college i started to avoid him as he was too much into me and always wanted me to love him. I clearly told him i wasnt interested in him and I had blocked his contact frm all my social media. But somtimes i used to feel pity on him as i knew abt his health issues and family issues. I never told him i loved him or i would marry him. But he always had this thought that if i didnt wana marry him then why did i keep in touch wit him. The only reason i kept in touch with him was becoz i felt pity. Later in my 1st year i also made my cuzn speak to him and tried to get rid of him. Many times i had blocked him and then he would contact again somehow. And from past 2 years i had completely avoided him. But i hav a number wich he knows. I havnt changed it bcoz my bank account is linked to it and i was too busy to change it. He hadnt bothered me much. Now i use that number to do online transactions and wenevr i use only that time i turn that sim on. And he contacts me through different numbers when i on that sim. I always cut his calls and blocked all numbers he called me from. I am 21 now and i got engaged to a person 4 months ago. This guy keeps torturing me so i picked up his call and told him clearly that i got engaged and i dont want him to torture me and look after his life. But he was not ready to accept it. He forced me to break my engagemnt and he sed he will speak to my parents eventhough i told him clearly that i would never ever marry him. After so much explaining he told me to marry the other guy but to keep in touch with him and love him. I was disgusted with this behaviour of his and i blocked him again as it was useless talking to him. So now that other sim card is with my dad and i dont want dad to think im in an extra marital affair. So i texted this guy in watsapp saying not to call to that number and that i would text him so that he wouldbt call.its really a torture to me to chat with him. All i say is to leave me alone. I never promised him that i would marry him or at the least i have never even been in a relationship with him. He is just obsessed with the thought of me and wants to marry me no matter what. Which is just impossible now as im already engaged and also i never even had that kind of feelings for him. I had considered him as a friend earlier thats true but ever since he started torturing me i just feel pure hatred towards him. I have tried many ways to avoid him by making my cuzn brother and friends also speak but this guy is just mad! He still doesnt understand and forces me to love him. I swear at him and scold him the worst way possible but he just annoys me. Is there anything i could do without putting myself in trouble