How do I dump someone?

For context: we met online, we’re friends actually almost 1 year then 4 months ago, he confessed that he liked me. I don’t know how to react because we’re close friends. We haven’t met, but we call together, play games together, and etc. so yeah, he confessed to me but I just responded wow that nice blah blah and really appreciated him. So yeah it goes on, we still talk but sometimes he’s being weird like he’s acting like he’s my boyfriend, sending weird stuff, and I find him weird. I had a thought just ghost him, so yeah I didn’t talk to him, I tried to block him in all social medias, but he would still end up spamming me asking why I did that and begging not to, trying to be pity and crying. So I felt really bad, the reason I did that is I really find him weird, it’s uncomfortable, and I didn’t think that he would be that serious because it’s online. but every time I try to ghost him and block him, he would always end up tryna get back at me. So I stopped trying, but still I want to dump him with him being offended.