Online Threats and black-mailing

Had been friends with this guy for 3 years since pandemic (who is supposed to be my old classmate). We both live in different cities and were minors for that time being. Used to chat normally as friends and communications were purely online through social media or sometimes call/text. In few months, he proposes but I reject and we stopped talking. He reappears and promises to control his feelings and behave as a friend with me. Again, we start chatting. From the start, his behavior was extreme, like if I don't reply to his message within short time, he would be mad. If I am online on any social media and he messages, I must reply or he starts spamming through repetitive calls. He again proposes me, this time too I reject him and also inform that I am not interested in him in romantic way and that I have a boyfriend by that time. Once again, he shuts up and starts acting like a friend with aggressive behavior. He would make me say 'ILYs', 'Good Nights', and 'Kisses emoji' as a part of our daily texting even though I didn't want to. The new addition was of 'Self-harm' like, if I won't comply to his order, he would drink mindlessly, and even attempt suicide in drunken state. Now that he knew about of boyfriend, he also threatened me to tell my family about my relation.(Once my mother caught me chatting late night with him; I come from a traditional brown family so it was sort of a big deal. She told me to stay away from him, but because he knew my secret, I continued to talk to him regardless). For third time, he proposed me and I had clearly told him that it was a big NO but he didn't seem to understand. He started to force me to make him a better person, just as my ideal type or else he would commit suicide. This lasted for 4-5 months and finally at one night, I told that I was not in the mood to chat and didn't wish him night...He dialled my mom's phone assuming I would pick up and answer from my mom's phone. I finally told my mom about everything. It was a big chaos. My phone was taken, literally my online social presense was blocked by my parents. Meanwhile, now that I was strictly offline due to this, he continued to message to my mom's phone from his number and his friend's number. Once my mom shouted on him on call to stop following me, he went silent. After 5 months of all this, I moved to a western country. I blocked him on every place where we used to chat. I unfollowed some of my classmates who were common between us. After my stay of 2 months in new country, one of the common friend who I unfollowed just some days ago reached me out saying he unfollowed me by mistake whereas it was me who did that. We did some chit-chat and he told me that the psychotic friend of mine commited suicide. I told him to see if this actually happened. Also asked another friend of mine to check on same. Turns out he didn't commit suicide and that common friend's talking seemed a bit suspicious. Next day, the psychotic messages my mom in my homecountry. Help?