As I have blocked a narcissist will he go crazy when he realises he has no more access to me

Yes, he will go crazy. Who wouldn’t.

Probably.

What about physical access? Is he still around?

In my experience he moved on completely unaffected. Couldn't hurt that ego even though I tried.

Tough titty. He deserves to be blocked

Yes, they thrive on control of others

It depends on if he has other fuel sources or not, might be hard to hear but they usually have back ups.
Just don't unblock him as if they feel slighted in anyway they try to get revenge.

This might be his reaction when he figures it out.

You had to do what you had to do. You cannot control his reaction but I see how it can be concerning. Hopefully he just forwards his interests elsewhere.