ANSWER:

Let him curse all he wants as this does not have any effect. Don’t let Satan mess with your mind to make you fall into sinning again. You have repented and Allah will accept your repentance and forgive you as long as you remain steadfast. 

I had a Male best friend in my uni. Recently I came across your vids from AskZad. They changed me I blocked all means of communication with him thou he still calls me with different caller IDs but I never answer. I was ignorant but Allah guided me through u. Now I observe niqab at uni n totally avoid him. But at times why I get thoughts like what if he curses me? Curses affect?