If the person you miss very much doesn't answer your phone, doesn't reply to your text messages and blacklists you … what should I do …

If I were you, I wouldn't call him, text him or blacklist him … but this person must be very important to you at first. You can try to contact him again. If he has been rude to you, there is no need to look for him again, although it is hard to forget that time will dilute everything now. Be kind to yourself and the people who love you.