Is freak a slur?

Hello Reddit, I wonder if you can help me. I was on Twitter earlier, engaging in some discourse with some ableist people (they used the r slur.) as a retaliation I called them freaks. Someone informed me in my thread that this word is a slur. I’ve done some research on it and the only thing I can find is its relation to freak shows back in the day. If anyone has any more information to educate me on this it would be really helpful as I don’t want to be blindly using a slur.

Disclaimer I am a disabled individual and am trying to learn more about the community:)