It is a personal attack for someone to repeatedly insist that you have no cheilik in Olam Haba.
It is no more a personal attack on you than your saying he was motzi shem ra was a personal attack on him.
In fact, you should be thanking him for pointing out that you were malbin p’nei chaveiro so that you can apologize and correct your behavior and avoid gehinnom.
(Based on:
I do have to say that I am puzzled by the fact that you have not once thanked me for trying to spare you from Gehinnom!!! Aren’t you happy that I let you know that what you said was Motzi Sheim Ra so that you can try to have it deleted and avoid gehinnom?)