How to handle a crazy colleague who got obsessed with crypto and is stalking me?

So, few weeks ago a colleague who never invested in crypto said he read somewhere that Shiba is the new Bitcoin. At that time, he didn't even know what Shiba or bitcoin mean. He had no crypto wallets, he was just making a random conversation about something he read online.

I made the mistake of telling him that I invest in crypto and that Shiba is a shitcoin.

Everything ended up there.

A week ago he read the news about the guy who invested 8k in Shiba and became rich and he automatically decided that now he would be a billionaire and he's not just because of me.

I never told him to not invest in Shiba, I just expressed my opinion. He never really wanted to invest in any crypto. However, even if he invested in Shiba a month ago, now he wouldn't be rich at all. But he's too illiterate to understand it.

Since then, he started to say that I made him lose millions and I should help him to recover (?!)

I just told him I'm not a trader and I don't give any financial advice. I really don't trade. I just buy the crypto I like and hold.

Since then, he started to text me everyday about any possible crypto and asking me if he should buy it. I always answer that I don't know it.

He thinks I'm just selfish and I don't want to help him because I want to be the only one to become rich.

He became very annoying so I blocked him in every social and I told him to not bother me anymore. So he just started to send me emails in my work account where I can't block him because he's a colleague.

Few days ago he sent an email without any text, in the subject it was written "shibazzilla: should I buy it?" I didn't answer him.

Now he told me he lost everything invested in shibazilla and he said it's my fault because I didn't warn him.

I told him "I just ignored you like I told you, I didn't tell you to buy it" and he said "so you had to talk when I was going to buy Shiba but you didn't think to tell me anything when I told you I was buying shibazilla"

He clearly got obsessed with crypto and he's too illiterate to understand anything.

I have no idea how to handle him. He clearly got crazy. I literally told him to not bother me and that I blocked him because he's not my friend, but he doesn't care. He's doesn't understand it. He says I'm kidding and we're all "crypto brothers"

I'm afraid soon I'll end up beating him and then I'll lose my job.

Any advices? Maybe someone had a similar situation?