How to end this?

I made a really bad mistake. I let my curiosity get the better of me and got involved with “a bad boy”, and now I’m stuck in a secret toxic relationship.

I want to end it. We’re fighting almost every day, because I don’t “listen” to him.

He’s said things like this on multiple occasions: “I’m never going to let you go. If you block me, I’ll come and find you. Watch out.” “Watch what will happen when you walk away” “You will see”

How seriously should I take statements like that? Maybe he’s just talking nonsense and thinks it’s romantic?

I don’t mean to offend anyone, and I don’t even know if this is relevant because I don’t know enough about it, but he smokes a lot(!) of hash and weed, around 10 grams a day. I don’t know whether that has anything to do with his behavior, but I thought it might be worth mentioning.

The thing is: Absolutely no one around me can find out about this (!!!). We come from different backgrounds, and this could seriously ruin my entire life.

I’ve learned my lesson. This will never happen again.

But how do you end something like this?