I think i might be homophobic

I've never thought of myself as homophobic before, I have  loads of gay friends, but today I accidentally used the word "f*ggot". I was referring to my best friend. They are straight, if that makes it better. I use the word "gay" as an insult but not to be homophobic, it just sounds funny. I love gay people, I just think i might be homophobic.