I told a cab driver off because after I asked him to move his vehicle a bit forward so I could park, he told me that I had more than enough space.
Is there a reason for being so mean to him?
He called me an asshole, so I got really mad at him
That sounds frustrating and both of you should have be more polite in the future. It does seem he is the one who was rude to you first.
I started out being polite.
Even though the cab driver called you a bad word and you felt frustrated, you shouldn't have told him off. Getting angry only escalates the situation and pretty much ensures that you won't get what you want, in this case him not moving his cab.