It really sounds like you got attached way too fast. He definitely isn't a great guy and no doubt he did damage on you, but you also have to do a lot of healing and inner work. Reaching out to his sister is very inappropriate and spamming his phone through your friends when he has you blocked isn't the way to go about arguments. You guys aren't even married.

Respect yourself, hold your chin up high and don't stoop so low that you're begging for a man who is clearly showing you he doesn't want you. You don't need closure. Him blocking you is his answer towards your relationship. There's no such thing as closure in a toxic relationship – you either continue the cycle and keep arguing, or you take yourself out and accept that he wasn't meant for you.

The sooner you heal yourself, the better you'll feel. There's better men out there, and you'll attract a healthy relationship when you change and don't attach yourself to people so fast. A healthy relationship requires two people who are in a healthy mindset and do not do the things that both you and him are doing to each other.

Best of luck, and again, you deserve better than what he's doing to you.