AITA for refusing to hug my mother?

I (m18) upset my mother by telling her that I didn't want to hug her.

Backstory: My mother has always been a hugger, and when I was younger I used to just put up with it but as I got older I have started saying no more. Back when I was in middle school my parents sent me to therapy for depression, but another thing that came up with the therapist was my issue with hugging my mother. The therapist recommended that she ask before hugging me instead of just going in for it or approaching me from behind (which freaks me out even more). My mother is fine with this in theory but gets upset whenever I say no, often giving me the silent treatment or stomping away.

The reason I think I may be the a-hole is that I am fine (sometimes) with hugs from my dad. I feel more emotionally connected with him and it just doesn't make me uncomfortable unless I am having a particularly bad day. I try to avoid hugging him in front of her so she doesn't feel left out.

Anyway, they were just about to leave after having dropped me off at my college campus. My dad hugged me and then my mother tried to go in for a hug but I backed up a little and said I didn't want to hug her. She didn't say anything after that, just got in her car and slammed the door. She hasn't texted or called me since, although we used to text somewhat frequently.

AITA?

Update:

For clarification, I didn't initiate the hug with my dad. If I had had more time to think things through in the moment I would have avoided hugging him to avoid the trouble with my mother. I honestly was not expecting anyone to hug me in that moment as I was carrying my bags and thought I would drop them off before coming back for a proper goodbye.

I have had a strained relationship with my mother for a while now, which I'm not going to get into the details of. I do make an effort to show her affection in other ways because despite everything she is my mother.

Generally my dad is supportive of me not wanting hugs from her, while in this instance he felt I was in the wrong.

I have a younger sibling who still lives with them.

Also, it is not like I hug everybody except my mother-- my dad is one of two people I am okay with hugs from.

Thanks all for the advice and perspective.