“I was getting bored and decided to message a guy I saw on a tv show in my country. It is a famous tv show worldwide. The guy replied, little did I know, he actually won 1 month into us chatting. I met him”
^Yes, I did something similar. . He wasn’t exactly a complete stranger, and nothing came of it romantically. He’s still my fb friend. But this is a really bold thing most people wouldn’t do.

“MANY people show hatred towards him due to his behaviour in the show and overall vibe that he has, maybe they are not wrong...)”
^They all can’t be wrong, take heed.

“ , he kept telling me he is busy, cannot pay attention to himself and to myself, but I rented an apartment to come see him! I told him I can help him with anything he needed ”
^Here is where you started to hurt yourself. You may have done this because you were star struck that he is famous. Yes, I had crushes on guys long ago, who were lukewarm about me and I also offered to help them. I secretly hoped they would see I was so good to them, they would love me...but they didn’t. The same happened to you.

“ bought him expensive presents for his birthday and he didn't even invite me to celebrate.”
^This would have been the final straw for most anyone else to give up on the guy and see how he doesn’t care for you. Did you still pursue him and why?

He’s intentionally being cruel by not answering your texts, at least to tell you he’s not interested and good bye. Do you think he’s ignoring you because you’ve been scary aggressive? (I’m not suggesting you are, just looking at it from both sides)

“I am.overwhelmed with this feeling of rejection, of "you are not worth my words".
^I’ve experienced this too. It’s severely painful.

I wouldn’t say I ever ‘chased’, but I did pursue and was more into the guy than he was into me and it always ended with nothing good happening. After getting hurt like that, I learned not to do it again. You’ll just have to work on building your self esteem and watch for red flags that the next guy shows, then you’ll know that relationship is not going to give you what you want, rather will hurt you.

I hope you feel better about moving on from him soon. He’s really not worth your tears.