Have I been hacked?

Hello,

Someone send me an email telling me I have been hacked..

It all seems nonsense

A (He hacked my PC, he says, but that seems not true, as he would have used ransomware

B he told me my old password was my password but it is an old password from long ago)

C he didn't change any of my details in my hotmail account (or any other accounts).. no recovery email change, no password change, and so on

Only thing made me believe him was that the email he sent from is exactly identical to mine.. even when I try to click to have the real info.. it stills shows mine

I had a nice idea to download eml.. put it in viewer to say what the real value is.. ' from ' part is identical my email exactly.

Note I tried the feature which view actual account sent from when clicking the first one.. other emails show normally 

This persons email, however, still shows mine

Someone told me this spoofing can work against outlook it self without detecting actual address.

What can I do to confirm that this is a non harmful claim of hacking..

Please note I am securing everything on my PC, accounts,.. and already started using 1pssword